Won't be Molly because her skills would be too ninja lol, this game isn't about jumping around rooftops and being a total zombie assassin, it's more about the storyline and the scare factor. And like someone else said, her story has been told, not much room for character development. That said, there is no reason why she couldn't make an appearance, not sure how they would work around that though, because she could be dead (although I doubt it)
Christa and Omid... They are more fitted as characters that are controlled by TTG, I just think that it would be.... I don't know, I wouldn't like it... There is a lot of character development available here, however I just think that we would have to start from the beginning of the infestation to find out how they met etc, and I would feel like all my character went through was wasted and I had wasted my time progressing through the game.
Clem is the most likely protagonist for season 2 because she is young so lots of room for you to shape her life, and TTG left it on a cliffhanger at the end of episode 5 and she is a much liked character, and I just feel like she is the right way to go... I know lots of you will disagree but this is much about opinions and a lot of you have opinionated your reply, so no hate about how I'm a retard or some rubbish like that...