I will be adapting the original game as faithfully as possible and continue the story from where the original left off. I plan to improve the pacing and better telegraph any significant upcoming events and changes in character through fleshed-out dialogue and choices. Also, I have no plans to change the tone of the game. The goofiness will stay intact, but there will be some shocking or depressing moments later in the story only because of the kinks/fetishes involved.
My current plan is to cut the half-assed vanilla route entirely and instead provide vanilla endings (diminishing) at specific intervals throughout the game. Doing so will make it easier for people to opt-out of the increasingly hardcore fetishes portrayed when progressing through either of the paths. For example, the feminization path leads to increasingly hardcore/niche fetishes such as Sounding, Pegging, permanent chastity, permanent denial of sexual intercourse, temporary/permanent bodily changes, etc.
So before things escalate, depending on any hesitation you might have shown previously, an unavoidable confrontation will happen with Emily or other characters. You can then choose "I don't want this" or "This is too much." Depending on how far you've progressed through a path, you'll get a vanilla happy ending, a less happy ending, a bittersweet broken family ending, or a "we should go our separate ways" ending.
As for the other project, I think there's a discord link to that project's group somewhere in this thread. I don't know much about it.