Thanks for your comment.
Recently, I've adjusted the arousal gain rate to be faster. This update will be released on Apr 26 (though I'm not sure if it will match your expectations yet).
As for Elf customization feature, it's definitely planned, but I will start working on it once the core gameplay is mostly complete.
Regarding fuck machine, milk machine, and futa—I'm afraid they don't quite fit the intended atmosphere of the game, so they likely won't be added.
I hope this helps you decide if the game is right for you!