SPOILER: Running a Country
A superhero is like a military unit with one brain and one body. Some are the equivalent of a platoon of infantry. Some are the equivalent of a tank division with full air support. There are three things that keep the military from taking over in any nation where they have not in fact taken over.
The first is indoctrination. Stable nations go to a lot of trouble to teach everyone that military force should always be subordinate to civilian authority and possibly some kind of constitution which has authority over the civilian authorities. American comic books and their foreign imitators instill in children the idea that while superhuman powers may entitle you to bend the law in the service of "justice", they _never_ entitle you to make the law.
The second is a lack of unity. Military leaders have to be confident that they can personally swing enough of a following to pull off a coup before they'll try. If your super population consists of just a few uber-powerful individuals, Kryptonians, or something, then it is fairly easy to organise a takeover if you can just persuade a few friends to go along with it. If you have just one Superman (or Von Doom), then it becomes child's play. If on the other hand you have a fairly large population of individuals of more moderate powers so that they can't entirely shrug off the threat of conventional firepower then it becomes far more difficult to organise a takeover and the risk isn't so tempting.
The third of course is a lack of inclination, separate from indoctrination. Regardless of whether you think it is wrong to take over, actually taking over the administrative duties of government is a time-consuming pain in the ass, and most heroes (and villains) have absolutely no abilities that would make them actually more capable and successful at running a government. How many people would want to spend hours a day shuffling paper without any clear idea as to whether they are accomplishing anything when instead they could be out flying around trashing "bad guys" and rescuing people and modestly accepting their thanks?
Consider Sailor Moon. In her future history she really does "take over the world". She becomes the queen of Earth (stepping into the power vaccuum left after a massive catastrophe that kills much of the planet's population). Now I've seen a lot of Americans react negatively to that idea. After all "we had a revolution to get rid of foreign monarchs yadda-yadda". Sometimes they write unfanfiction about it where she's portrayed as a tyrant, implausible though it might be that someone chiefly characterised by profound empathy for everyone she meets and a lack of inclination to do any mundane work, would make a likely tyrant. But consider that Naoko Takeuchi was born and grew up in a monarchy where the monarch in question has historically played little or no role in the actual administration of their supposed realm. For the last thousand years or so, Japan has had a grand total of one emperor who actually ruled. For the rest it has been shogunates, and military juntas, and for all of Naoko Takeuchi's life, a parliament. Although NT doesn't go into details about how the future works, I would expect that while Neo-Queen Serenity may her face on the all the money, in peace-time (which is most of the time) she no more rules the planet than Queen Elizabeth rules Canada
So, maybe the heros do take over for a while because the normal governments have done something stupid like trying to launch an anti-mutant pogrom or trying to declare World War III and launch the nukes. But if they do, they'll soon find that actually running a large government is a frustrating, and time consuming business even if the public is entirely behind you and one that they haven't actually been educated to do and aren't all that interested in. What's more, they are so personal powerful that they have little to fear in the way of consequences from giving up governmental power. So the natural thing to do is to hand over the actual responsibility to people who are interested, educated and experienced. For Western heros (and military men) that naturally tends to mean holding elections and turning over actual authority to the winners.
Take this and run with it in a slighty twisted direction and you get...
-Metahuman registration not to keep track of dangerous mutants, but to let the supers know who they have to call upon in time of need. After all, don't these people have a duty to help others? If you're a metahuman and you're not registered, what have you got to hide?
-Metahuman children who are taken from their parents 'for their own good' and sent to an academy to be trained in how to 'properly' use their powers. Of cours, training to use their powers includes instilling in them a sense of their moral obligation to soceity.
What about the children who's powers are too powerful, unstable, or downright scary to be allowed to potentially endanger the world and themselves? Would you end up with Super Psycho wards, would they be forcibly cut off from their powers, or would they be sent to play with some kids in China (you know, 'youth in Asia' ). If Supers are in control and have the power to do anything, how long will justice last? Would they begin to see themselves as gods? What would happen if the 'normals' tried to retaliate? How many would be left in the aftermath?
Remember... Good can be as tyrannical as evil.
What if the weather manipulator crosses over various sovereign countries to grant rain to one drought-ravaged nation, while others, who are foes with that nation deny her the right to cross their airspace? What if the animal-controller begins teaching whales how to avoid whalers and coordinates their responses so that if one gets harpooned, they turn on the boat that speared their podmate and swamp it? How are the various labor unions going to agitate against a telekinetic, speedster or strong-man who can do the work of a hundred, or thousand, men in a day? How many trained heavy-equipment operators are going to find themselves out of work when a crane is no longer needed, since Jimmy the telekinetic can lift the girders into place, and pyrokinetically weld the rivets in?
Biggest issues are going to come with entrenched organizations, like the AMA, preventing healers from doing anything without a medical license, which they will end up stripping from any actual doctor who develops superhuman healing powers (always citing some procedural irregularity from 10 years ago to 'justify' their decision).
Other places of contention would be the abilities of telepaths and clairvoyants and even postcognitives to violate privacy. Have sex anywhere and a clairvoyant could be watching right now, a telepath could see it in your memories later and a postcognitive walking into that location years later could see it in a flashback. And it isn't the sex that people kill to keep secret, it's the backhanded dealings that go on in corporate and political circles. The people who make the laws have the most to fear from secrets getting out.
It seems inevitable to me that superhumans in a world like ours would be regulated into impotence, in some Harrison Bergeron-esque circus of outrage from 'normal folk.' And as inevitably, some, ranging from empathic healers who refuse to abide by AMA restrictions not to 'practice medicine without a license' to destructive psychopaths sick and tired of being told what they can't do, are going to break those laws, and reinforce the notion that those laws, and more like them, are needed.
Ultimately, I see a 'superhero' team as not being seen as heroes by a lot of the populace, and not even being a 'team' in that they don't really have that much in common, other than occasionally rallying to deal with some sort of 'meta-threat' like a government (or religion) going after superhumans en masse. To use the above examples, the weather controller is going to be flying around doing his thing, redirecting weather patterns for the greater good (and yes, the greater good means preventing starvation, and not providing good golfing weather, and it isn't the people starving that have the means to legislate an end to his works, it's the people golfing...). He's most likely going to be working globally, and not have a whole lot of time to hang around the JLA Satellite / Avengers Mansion. Ditto, the animal-loving lady is going to be on the move as well, teaching various animals ways to co-exist with humanity, which may often lead her into conflict with nations that oppose her works (such as the previously mentioned whalers).
One factor that *could* unite them is a super-intelligent mastermind, who sits in the base and lays out 'plans' for them where they can accomplish the greatest results with the least 'effort.' So if the mastermind has figured out that the snowcaps of the Himalyas have something to do with the monsoons sweeping over India, he can tell weather-dude to stop 'putting out fires' over India and get his butt to the mountains and make a more direct fix to the overall problem. Instead of animal-lady saving one animal / pack at a time, he can lay out strategies by which she can save entire species / ecosystems. That would give them a built-in base to rally around, since 'brainy' is an integral part of their success, and the reason that they aren't always running around trying to fix everything all at once and dropping dead of exhaustion trying to keep up.
It would be very true to the genre for 'brainy' to have his own agenda, and to subtly direct the team to his own ends... Whether those ends are sinister, hard-nosed, practical or Ozymandian, would be a matter for the ST to determine.
superhumans not just being stronger and faster and tougher than any human ever can possibly become, but some also being smarter and wittier and more charming and charismatic than any supermodel / dictator / idol-of-millions has ever been.
So when the UN-adjunt organization in charge of superhuman affairs wants to deal with something, they send in Geisha, a demure Japanese woman with enough stately presence, gentle grace and the power of an emotional steamroller to make Saddam Hussein roll over and bark like a dog. When their PR department wants to present superhumans and the near-vigilante-status of their costumed agents as being 'good' and 'trustworthy' they have people on hand that design a marketing plan / PR blitz that matches Tony Starks genius at building shiny metal boxes. Even a clever and skeptical person is as likely to see through their media campaigns as a pro boxer is to punch out Iron Man.
A game slightly less centered on the overwhelming superiority of 'mega-social' abilities is still going to have the average person tugged willy-nilly by competing agendas. One news report might focus on how your neighbor could be invading your privacy with his godless devil-powers, while another channel is showing a couple of superhumans saving thousands of lives from monsoon flooding in Bangladesh. Once a superhuman with an interest in PR, and in keeping his own hide free to use his abilities, comes to the fore, a whole new world of spin doctoring is going to manifest, one in which the truth becomes increasingly obscured.
Events could be manipulated (or simply taken advantage of and expounded upon in the media) to introduce legal protections for superhumans, or to restrict them. 9/11 brought about the Patriot Act, which took away some rights that our Founding Fathers quite literally compelled us never to surrender without a fight. In a world where an event like that could occur if ONE superhuman got a wild hair about something, 'Patriot Acts' could be a regular occurence.
Depending on whose manipulating whom, the superhumans might find themselves with broad sweeping powers to hunt down and deal with threats, foreign and domestic, and indeed these 'Enforcers of Liberty' might find themselves increasingly hamstrung by the legislative bodies that hastily empowered them. As the legislators become increasingly frightened of what they've unleashed, and start trying to cram the genie back in it's bottle, the genie might start to fight back. Some might earnestly believe that the government is trying to keep them from doing their jobs, because of internal corruption and officials 'in bed' with the same forces that are threatening the people. Others might simply be frustrated with being sent after targets, targets who are shooting at them, and possibly involved in acts of terror and whatnot, and then told, 'oh wait, but you're not allowed to violate their rights, or the Geneva convention, or do anything to upset public opinion of my administration.'
Increasingly, a 'military coup' by superhumans seems inevitable. 'For the greater good' becomes the rationale for increasingly draconian measures by the superhuman agencies. If they have to break some laws to save a thousand, or million, people, then they do so. (And the trap is sprung. Once you start 'saving them,' when do you stop? You stopped the flood. But their homes are still wrecked. You rebuilt their homes, but they're still starving. You airdropped them food, but disease is at epidemic proportions from the flooding and squalid conditions in the refugee camps. You brought in medicines, but they are still oppressed by warlords and looters. You overthrew their despotic government, but they are still jobless and uneducated. When do you get to leave? When do you get to rest? Do you have to *order* them to stop having a dozen children only to see 80% of them die? Do you have to change their very culture to stop the spread of HIV? Do you have to ban their religious practice of bathing in the Ganges because it spreads malaria? How do you prevent them from slash-and-burning their forests, or overfishing their harbors, or polluting their rivers? When do you stop 'saving them?.')
If the CIA / FBI etc hire just a few superhumanly intelligent / sneaky / etc people, how on earth can they, merely human, be expected to keep track of them? How long is it before the telepath ends up knowing where *all* the skeletons are buried? How long before the superhumanly smart analytic genius ends up moving his superiors around like pawns, simply out of boredom? How long before the cyberkinetic hacker infiltrates all of the government intelligence networks, out of a simple desire for efficiency, and puts together things that a dozen rival covert agencies never could?
The impact on religion is potentially the most sensitive topic, depending on your players. Aberrant assumes that Hindu faith generally embraces superhumans as new avatars of the godhead, that the Pope has recognized superhumans as 'as human and as flawed and capable of grace as the rest of us' and that other sects, Muslim and Christian have declared them to be anathema, agents of the devil and / or signs of the end times.
It is pretty much inevitable that there will be entire churches built around the notion of supers being a sign of the end-times. Devil-spawn using Biblically proscribed abilities of sorcery and prophecy and such. We spent many decades working up to acknowledging that blacks were human and had rights. Then it was women, which many individuals (and a few cultures) still maintain should be subservient to men, shuffling around in black robes and keeping their mouths shut. This week it's gays. 10 years from now, we'll be railing against those godless southpaws and their stubborn freakish insistence on using their left hands for everything. So a man who can fly and shoot fire isn't going to get away with that sort of stuff around 'decent folk'...
