I don't know how much you've thought this through, but how is our little team going to be united? I'm guessing we were originally independent heroes who banded together, rather than being friends before we got our powers, but what is it draws us together? Is there some sort of crisis that requires all of us? Has the government offered us funding to work together? Are we a corporate-sponsored team?
Could we GET corporate sponsorship? 'Cause some of my concepts could be pretty mercenary, and I like the idea of having corporate sponsorship...
More than anything, I'm wondering if we're working within or outside the law. If we're outside it, I'd have to rethink one of my concepts (joined the team in lieu of a jail sentence for reckless endangerment). It'd also raise questions about where we get all our wonderful toys and costumes from. Also, do we have secret identities? I know they're a staple of superhero works, but they do have some problems when you think about them (it's really easy for criminals to find them out, and when they do the police won't know to protect our families 'cause they're not allowed to investigate)