It's highley recommended that you start a new save since there's new code that old saves don't recognize
If Luth doesn't reach affection level 7 before leaving for zone 2, she becomes disinterested in you and you can't progress
I believe just click sex battle, use your AP points for the day, then sleep and she show's u
It's in the antler
The story so far hasn't gone past the desert as it's still in development, so you're pretty much finished for no