Yeah, I totally get you. Those big corporations love milking players with overpriced expansions, lazy DLCs, or “modders” selling stuff made mostly from someone else’s work.
For me, Patreon is just a way to fund development and keep the project alive. It’s more like early access support than corporate monetization.
About your gameplay question => Different routes (Love, Lust, Domin...) lead to unique scenes and dialogues with each girl, and certain dialogue choices can unlock bonus favor points.
There is an optimal route that lets you max out every girl’s score, but it’s intentionally designed to be pretty challenging. For your first playthrough, I’d recommend focusing on two girls to get a better feel for how the system works.