I think that may be an issue with the phone menu blocking interactions, which I think I've fixed in 0.8
Glad you're enjoying the game!
The multi part idea is actually something that will be introduced with the penetration scenes. I won't be doing any expressions that seem out of character. So don't expect someone as proud as Lillith or as timid as Catherine to ever beg for a creampie (just as an example). I want the characters to be true to their personality even when it comes to the sex dialogue, and I'm hoping so far I've made them all distinct in how they act and react.
You certainly can - is it not working for you?
Glad you like them! There are still plenty more NPCs to come too and I hope you'll enjoy them as well ^^ As for futa, most likely not.
Having to choose is being removed from 0.8.
Can you post a screenshot or something similar? I'm finding it hard to understand what you mean.