as far as I know, no you have to make choices for both of your character
1/3 of the game is available in the b黎a, I have not seen the end so far. my longest session is about 10h but it was still alpha stage.
and yes when the game will be release, all the beta save will be incompatible with the release version
I'm pretty sure I remember them saying you can let the AI run one of the characters' responses which goes in hand with being able to assign them personalities.
