I hope this doesn't come across as too critical, but I feel you're focusing on an interesting - and even elegant - mechanic rather than the stories you want to tell.
Will you be better able to tell superhero stories with this mechanic? Does it better capture the comics you enjoy reading?
If not, I'd scrap it.
(That said, there is joy in mechanics for mechanics sake. It's just not joy for me.)
To answer your second question about other superhero games, try http://yearoflivingfree.info/superhero