Is it possible to have a romantic route with the mother without having to subjugate her?
I expect the NTR to be avoidable (ie, it doesn't happen if the player wants it to), unless it's the MC stealing other guys' girlfriends/wives. And the same if futa characters are included, that can be avoided.
Not yet, the best you can do it's seduce her by upgrading your mind, she will lust you.
Every girl will have two main base stats until half of the game, then you will be able to mix with another.
see more about here: https://ojot.itch.io/cursed-love/devlog/577422/status-system-010