Speaking of women in fridges, I think we could see Pepper bite it in Avengers 2. She's almost done, RDJ will only have one movie left after. Kang explains recasting, interestingly enough can explain recasting, bringing in a younger version of Tony, or an alternate someone else. Cap can be replaced by BuckyCap pretty easily, and Thor can be brought back with Asgardian Tech. Kang can bring *anyone* back, as you said, so there's that too. But to be fair, that's not really "killing off" characters per se. They get killed, but they come back the very next phase, really.