Valygar/Viconia will come to blows because Viconia is a bitch to Val, so you moght want to keep them apart for a bit every few days or so.

Edwin/Minsc, Ed wanted to kill Dynaheir, Minsc's witch. So do the same above with them.

Massey? Do you mean the Halfling Fighter Mazzy? Oh wait, nevermind, custom character. If you have Nalia or Aerie, Minsc will adopt them as his witch at some point.