Hah, I have no idea if I can take this any further, but Coulson could probably slide nicely into that sort of role. I'm trying to come up with what a Firefly-verse Tony would be doing - has he set up his own little fiefdom on the back end of a moon somewhere, or is he nestled into the heart of a metropolis, a power player? Is he like Mr. Universe but with more robotics and less information purveyer?

And I'm a bit at a loss regarding Thor and Steve right now. I think there are many places they might could go, but none of them feel right just yet.