I was thinking that it start off like Skyrim where something is happening with your character caught in the middle but no connection to anything. When they need to get out because something's exploding then one member of both teams at either end of a hallway offers to help them but they have to leave now.
Depending on how it goes the character could join either one and both have their own good and bad sides. One would be the 'villains' side but they aren't that bad and the 'heroes' side should be about the same. They're just people under the costumes. Your character could influence them in a few ways, like encouraging certain interactions between members or just being a psycho and trying to make them betray and kill each other. Depending on your actions, you could get kidnapped by the other team and if they like you then your original team could break in and rescue you, even if if was the villains breaking into the heros hideout.
As for the book, it's mostly done and I just need to modify some of what I had to the backstory I've been working on separately and work on the ending so it isn't as compact as I have it now.
As for Soapys idea, I was thinking about how when you balance your life you play like Peter Parker. You need to do your Super stuff but you also need to pay rent, eat, ect. You would need to figure out if you can leave your job to go help someone or risk getting fired by vanishing on them.