I can answer both those questions actually, Ashton is kinda freaky because the game and character he was inspired by was from an erotic VN called "Your Boyfriend". It's a little controversial and very adult and I didn't want my game to be THAT adult but still wanted to have a tiny bit of spice to it. At the time Ash was getting a little too delusional, I also left it up to the players imagination as to what he was saying.
The character that inspired Ash would be Peter from "Your Boyfriend", Peter is technically my firt VN yandere, I've never seen a male character that's already SO MUCH in love with the player and would murder the other characters. Back in my day (old lady voice) most yanderes were female and very similar to Monika, but the main reason I made this game was to make a similar character to Peter for people to enjoy as a comfort character. And Ashton HATES that, he hates Peter, and even says "do you know how hard it is to eat with teeth like this?!" Poor baby. But also Ashton is a bunch of things I personally love, he's a heavier/fatty guy which you really don't see a lot of, and he's a big nerd with a soft spot, with my favorite color of eyes♥ He's actually way more similar to Underfell Sans from fan stories of Undertale whom I love very much. I would joke that Ash's "father" isn't actually Peter but Underfell Sans and thus his last name became "Fell"♫♪
Yes Vincent cross-dresses. Despite always talking about "the code of the gentleman" he's very comfortable wearing women's clothes for their elegance, maneuverability, and fashion. The line about the heels he's embarrassed about because they are only for fashion. Rats? Does Vincent like rats? Hmm, I would say no only because "all animals except rabbits" frighten him. You could probably get him to tolerate a domesticated rat (i personally LOVE domesticated rats♥♥♥).
Oh ok, then I think that's at the very, VERY end near the final scenes, it's very heartwarming♥♥♥