I would love for Kylo to survive this film (preferably dark, but light would be alright) but I think it's inevitable that he's going to die.
I don't think that they would end the saga with evil reigning (even with RotS you knew what happened after it).
I am not sure how he will be defeated though. If Rey beats him again, there might be more outlash from fans, though she is most likely to do it. Luke is dead so we can rule that out unless he pulls a Yoda. xD
It may be possible that his group, the Knights of Ren, finds out about his betrayal of Snoke and they end up killing him or maybe even Hux will do it (which is something I DEFINITELY do not want to happen).

I don't think Han will come back. He was stabbed through the chest by the most dangerous hand held weapon in the galaxy and fell down that giant shaft. Maul was able to survive something like this but his pure hatred of Obi-Wan and the his trust in the Force kept him going.

All in all, I believe the good guys will come out on top with or without Kylo.





ps: sorry if I made any grammatical errors, I'm posting on a phone =P