Hey, thanks for playing!
The whole Brothel/King's Remains thing will be expanded as the game gets updated. Princess sells them so players have a repeatable source of them to unlock future scenes there, among other reasons.
Also yeah, I'd say visually Princess' scene was the one I was actually unsatisfied with. I feel like I struggle to make non-animated sex scenes dynamic or impactful. I think in the future I'd like to re-draw that one or bump it up to a full animation maybe.