So... about the new content. I am genuinely unsure what I am supposed to do here and waiting for a walkthrough.
As for questions a and b...currently unknown. What I can tell you is that if you side with him, he does not currently backstab you nor is there an option to backstab him...yet
For c, Both paths are equally valid, I don't think there's ever been a true path with other branch options
For d. No, she isn't lying
E. She does not love her stepdad. She's doing this because of her mom who she believes is being held hostage.
regardless I chose the path of telling him to fuck off. both route do have ntr potential though the second route probably has more of an ntr vibe