Thanks for this post, really!
It's really hard to get some opinions on the female part other then from hetero-male players. I always found the lack of lesbian female games really... frustrating? So even though I'm writing this from a male perspective, the female MC was always meant to be there and I'm trying my best to make the story, scenes and dialogues fit for both characters.
As for Rachel, you might have noticed that there are several choices that don't change the outcome of a scene, these choices will change how Rachel (and others) will act towards you later in the game. I've actually just finished the first scene where Rachels dialogue changes slightly depending on your choices earlier in the game.
MC's submissive side will show in the future if you take the right choices, but please don't expect too much, I'm more into the opposite and the sub part is a lot of extra work^^
Kat is a little tsundere that developed some specific kinks through her "Memories". Next update will clear that up a bit ;)
Again, thx for you post, I really appreciate your thoughts!