I don't know how much you know about RPGs in general, so I'll keep this basic.
1) Creating characters is fiarly straightforward. Put points into things your character can do. If you want an easy character, use the pre-generated ones in the book. If you want a customized one, make it yourself.
(if you don't have the book, I'm assuming you don't know about the rules)
it's like D&D: you have a list of ability scores. Everyone does: strength, Dexterity, Constitution, Intelligence, Wisdom, Charisma. If you have a higher number, you're better at what you do. Even better than that, you get a bonus to die rolls when you attempt to do things related to that stat: Strength is for lifting or smashing stuff.
Therefore Jimmy Olsen (10) has a lower strength than Batman(18, if not 20); who has a lower Strength score than Superman. (45+ other powers that increase his weightlifting ability).
M&M lets you pick whatever your stats are, but putting points into different abilities. Not only that, but you can put points into skills (like using computers, sneaking around, and knowledge) and powers (shooting laser beams, flying, super speed, invulnerability, etc.). Also you can get Feats (rules exceptions: you can do something other characters without the feat can't).
As you play the game, you get more and more points as a reward. You could say this means power levels increase; for other RPGs like D&D this is expected. However, comics characters rarely "change" per se. You could find yourself with enough points to finally do what you'd wanted (ie: Batman gets that rocket car); but you could also find yourself with more points than you needed (Wolverine has everything he needs... but since you need to spend those power points, suddenly he gets magic laser vision or something).
This is very open, and in theory can mimic how virtually any comics character works. However, it's easy to use a few points to do more powerful stuff than you'd expect. Likewise, you can do something with a few points, or the same thing with more points; if you learn the system you can "cheat" in some nifty ways.
That said, things can get wacky, much like the comics. It's all for fun. The comics do tend to nerf stuff a lot. You could say that the same character has a different M&M 'build" with every writer or with every story. Sometimes Superman is super-powerful; other times Batman can beat him up. So you'll see many very-different ways of building the same comics character.
2) If you want pre-generated conversions, that is way easy: Atomicthinktank.com has two places I find with great lists like this:
Roll Callhas people's personal fan creations. Piles of them. Whether they are good or they suck is up to you to spot, but I don't have a problem with them. By the book, though whether they're overpowered or what have you, for *your campaign*, is up to you.
Another is
Fan Resources. Specifically I recommend the DC/Marvel pdfs. They're a collection of a pile of heroes & villains from both settings, statted out reasonably well, and with pictures.
The issue is whether you can make a character that's... easy for you to use. I like simple numbers when GMing. Some people are fine with other levels of complexity.
What you don't want is a character who can auto-kill, no margin for error, anyone even the BBEG. You also don't want a character who can't accomplish anything.
M&M is tricky. I think it's great for conversions of favourite characters, but it's so easy to lose track of what works against a group that all the prep time of monster-building can be lost in a heartbeat.
3) I played in a game for years. Literal years, in a play-by-post game on a different board. Loads of fun.
Thing of it is, the dice weren't handled by me. I hated doing stuff, so I picked powers that I didn't have to roll for: flight, transformation, immunities, that sort of thing.
I was lazy. That was silly, but it was fun just playing a character.
My issue is that the actual combat takes... well, thinking. Keeping track of whether something has however many hits; then removing a couple; then putting some back.
If I could change it, I'd... well, I'd have hit tokens that went down for PCs, so they couldn't get knocked out in one shot. It's easy to get knocked down if you roll a 1.
I also have shortcuts for minions and villains who aren't important. Buy books with pregenerated characters also, to save on prep time.
Otherwise... well, give it a shot. It's fun making up characters, and the system is pretty good.
You're the only one to talk about his PL.
