Well, people datamined that Jaheira is/was married to Halsin, so i can only imagine what's in store for Minsc. Maybe that he never really cared for Dynaheir, who knows.
That's an interesting way of looking at it. It's been about a hundered years since Khalid's death and in BG2 she is a romance option for PC. Why wouldn't she find another mate by now? That's quite a change in taste though. I also felt a great disturbance, as if millions of thirsty Tavs suddenly cried out in terror.
I don't remember there being any romance between Minsc and Dynaheir, unless his right of passage job as a bodyguards comes with unmentioned benefits.