I encountered the same issue with Volo's revolving dialogue. I've also encountered a lot of instances of characters forgetting they've had a conversation with you and presenting things like they're brand new information. Somewhat related but amusing is the inconsistencies in the codex. Astarion's exclaims that he's a vampire after its revealed in camp but the update from meeting the hunter is "Astarion might be a vampire!" I actually laughed when I read it.
Regarding the suddenness of the romances--I feel like it highlights the need for more bonding opportunities between the pc and npcs. I feel like we should get a few more instances that help define the relationship and how the characters act toward you. It's whiplash having a relatively friendly conversation with a character but then, because their approval isn't high enough, they great you with disdain when you start a normal dialogue. I feel like their responses to you should be linked more to these moments than to the approval system. (The two could work in conjunction with each other). It would feel more like progress if these moments set the tone for friendship,rivalry, or the triggering of the character as a potential romance option. This last point is the most important, I think, since some players are going to want to flirt with everybody whereas others don't want to be bothered with romance at all or don't want to be propositioned by characters they don't jive with.
