I voted 'no', but I had to think about it for a bit. I've never done anything with Minthara (except kill her) so I can't comment on that. The only time I ran into something(s) which felt weird and uncomfortable sex-wise was in Act III when the Emperor and Mizora both propositioned my obviously-uninterested-and-quite-hostile Tav. But that sort of makes sense for Mizora. No excuse for the Emperor.
Never did much with Haarlep or in the brothel. I'm generally uninterested in that sort of side content (I'm asexual and a bit sex-repulsed). Fortunately I could just... ignore it. And I did. Never had a problem with how or when any of the companions hit on my characters, it all seemed to fit the circumstances and their personalities - I think I somehow avoided a few of the more common and annoying bugs.
I was here for EA and remember it being much more awkward at the tiefling party back then. They've done a pretty good job of smoothing that out, in my opinion. So, overall, I'd say no, it's not overly sexualized. But keep in mind that I play a lot of "romance" games, or at least games with romance included, so my perspective is probably a bit skewed.
