I'll probably take you up on that. The first change I want to try making in my personal fork of the game is based on
this query. I want to make it so that when a girl is assigned to a client, the game makes a temporary list of all the videos in every eligible subfolder of that client's category (for example, if the client is asking for sex, and you haven't unlocked Anal yet, then it would make a list of every clip in the girl's FacingVaginal and BackVaginal folders), and then randomly select from that list, instead of selecting the subfolder first and then picking a clip from there (or else chooses the folder based on a weighted random of how many clips are in it). So the first question I'd have about where stuff is would be the function for what happens after a girl is assigned to a client and how the specific video file is picked.
(FYI, I have spent many hours working with Unity and C#, but I've mostly dabbled in simple turn-based games, so I have no idea whether this all will be far too complex for me or not.)