My money's on Sally being Rey and Corey being Kylo Ren, given the two start out antagonistic but grow closer over the course of the story.

I don't think Pete will be BB8; it seems too obvious.

Actually, I could also see the Pete = Kylo Ren, Sally = Rey, Corey = BB8 that was suggested above.

Don't really have anything to add for the rest of them that hasn't already been said.