After playing this game way too damn much I figured I'd drop some of my thoughts and frustrations while avoiding the obvious stuff that everyone else has already mentioned.
First off; please adjust the Bondage engine so that girls can gain Corruption and/or lose Willpower from Whips/Oral/Anal. Every single Bondage session becomes; attach Clamps, insert Hook, then spam Vaginal because doing anything else just wastes time and stamina. At least Whipping and Anal still give Arousal and Happiness but Oral is so wonky that I've never actually seen a girl gain Arousal from Bondage Oral, even when they're at negative Willpower and 100+ Corruption, so as far as I know it's literally useless.
Secondly; a frustration I've found is that the Wife Framework relies heavily on Intelligence and Discipline, which are two stats that the player has no direct control over and most girls have relatively low starting points for both, meaning that in order to have a wife who actually provides something useful you need to lock them up in the Academy for a few in-game years while praying for good rng. This isn't game ruining or anything but it seems like there could be plenty of fixes that could remove or reduce the annoyance, from more home schooling options to an item/drug that increases Academy learning speeds.
Third; I won't say much on this point but just be careful with the AI art. In my opinion it's perfectly fine when it's used for the small one-off stuff, like the end-of-day pictures or the bonus images on the captured slave menu, but having the entire Fort Sera story told using it was extremely distracting.
Finally; another frustration that becomes extremely hard to ignore in the later stages of the game is the lack of combat respawns, I know it was probably for balancing reasons originally but we have a million dollar investment available now, so a few more 'loot sacks' popping up on a regular basis isn't going to break the game. Something that could be fun and also alleviate this problem a bit would be to make the high difficulty monster enemies who already respawn drop a material that could be sold or crafted into gear/ammo since the meat they currently provide simply doesn't feel worth the time it takes to kill them.
I apologize if I sounded like I was whining since I really do enjoy the hell out of this game and look forward to its future.