1) lowkey NSFW stuff makes games more memorable for me especially since it really brings you into the moment as a player + you can emphasize zuzu and mc's relationship in a more particular and intimate way. it just makes it all the more immersive personally!!:D for these scenes,I would honestly just add some options that glaze over the nsfw scenes (replace with another almost equally as intimate of a scene except it's not sexual, similar to the ones you had for the demo like the kitchen scenes lmao) and still keep the important aspects like the lines exchanged, lore, or whatever need be so the storyline and immersion isn't lost with a gap of some sort.
3) honestly i really like the vibe with the current demo !! it's very cozy. I can see the storyline going down some kind of dystopian route but i'm not sure if I'd like to see that ahh. you can either highlight the characters more with the creepy scenes or the overall setting and world building a little more and I think I prefer the latter to perhaps emphasize zuzu and mc's relationship again since the game is mostly about them two at the end of the day! (I think I would enjoy anything you make though I loved the demo a lot and I can't wait for more!!)
4) the font was no trouble for me to read!:')