I just got to Kolima, and it was said that when the Golden Sun formed, most of northern Angara was destroyed. That would explain Lunpa. And it's possible that those other towns were destroyed in the upheavel of continental reformation.
Also, talking to Nyunpa and Briggs is AWESOME!! I lol'd that he still has the ship (that he paid for fair and square) from Alhafra.
EDIT: Didn't finish reading your post. Looks like we agree.
Also, he's a douchenozzle.