Hi! It's okay, we're always happy to see questions, though we might not answer right away.
First of all, nothing is going to happen to a romance. You can do any RE encounters you like.
As for the romances, if Haer'Dalis was meant to be a multiromance by the author, you can play both at the same time.
(But, and this is my position: if the player uses multiromance cheats and screws up Bodhi abduction by romancing Xan/Kelsey/Anomen/everyone else at once, it's the player's problem.)
As for that conversation, it didn't relate to Minsc or RE in general. That talk was meant for you, the player, to use, but only if you felt it was appropriate for you. It does not relate to any RE encounters or other romances, there are no counters/variables, the only condition is - you're in an active romance which has progressed past the 15 sequential lovetalks.
For example: Haer'Dalis romance comes out, there is no crossmod content, you can romance both at once, but you still want to talk about it. You click that conversation and confess to Xan.
In short: you're fine, just play, enjoy the game, and have fun!