Thank you for your lengthy replay! I hope I don't take up too much of your time with this conversation, so feel free to ignore this and simply enjoy your free time if this is too much text.
Hunger and fatigue are popular mechanics, but the issue I have with them is that they feel more like frustrating obstacles to the player than actual meaningful gameplay, often times merely dragging out play time, preventing progression and forcing the completion of meaningless activities. They rarely add anything to an open world game, with the exception of farming.
The non-adult survival game Subnautica for example handles this beautiful by offering an optional mode that removes hunger and thirst, but keeps all of the other survival elements. Since you're brainstorming about many things being optional in your next game, perhaps "tedious" mechanics could also be optional, for players who enjoy eating and drinking every five minutes. Again, just a suggestion. Perhaps you already have an idea for making it fun (e.g. by finding "alternative" methods of nutrition).
As an alternative to fatigue, I would suggest that each more significant action takes up one or several time slots. This naturally limits how much you can accomplish each day, especially in combination with actions that can only be performed at a certain time of day (or even day of the week if you want to go that far) and in specific places.
Godot has become a popular choice recently in the wake of the Unity licensing fiasco, but its documentation in particular is lacking compared to other engines. I first wanted to write that porting games to mobile isn't very convenient with it (not that this appears to be a priority for you, going by your comments), but this appears to have been fixed, so you could quite easily create mobile versions of your next title, which I think many people would appreciate, given how adult games lend themselves to being played more privately on portable devices and how many people don't even have a PC anymore these days. Ren'Py and Unity are easily portable as well, but Ren'Py has several advantages, being simpler to code, far more lightweight, free and open source - and (most important to me, since I like to fiddle with games) by far the easiest to mod and translate.
Your ideas about the next art style remind me a bit of Good Girl Gone Wild, except for using renders instead of photos as the basis. Is that what you're looking for? Painting over 3D renders and colorizing them in broad strokes?
I've always enjoyed the trope of a girl having to make it in a big city, so I'm looking forward how you can make it work. I don't mind the idea of a darker universe, with fetishes that would be perhaps a bit too extreme in your current game. There might be a niche for a game that combines this with your unique humor.
