Off the top of my head, Mel's ending path was something like finish her flyer quest, then talk to her 4 times during vacation (takes lower priority to familiar DM events). Date her in the last day. I might have miss a step in there.
Uriel is the only undateable one I can think of that has a portrait.
(Rogue Galaxy Board) shiva: Oh lol. Then you're the most dedicated troll ever on a board xD