When a party member returns to Tamilar to heal while in the middle of a dungeon it is my understanding that they do not recover any fatigue. Can a party member rest in Tamilar and recover their fatigue and then move?
Answered in the FAQ.
Q: Can a hero traveling to town via a glyph take any action before Restocking, such as attacking? Does returning from town still cost 1 MP? What other limits are placed on heroes in town and using glyphs?
A: A hero who begins his turn adjacent to or on top of an activated glyph has two options: take a normal turn or go to town. If he goes to town, he is immediately moved to the building of his choice and gets to Restock there. No movement points, no declared action – he just Restocks.
A hero who begins his turn in town has two options: Restock again (at the same or a different building) or return to the dungeon. If he returns to the dungeon, he declares a normal action (Battle, Ready, Advance, Run) and then must spend a movement point to move from town to the dungeon, just like normal. If he somehow can't do so (i.e. he Battled and had no fatigue left) then the entire action is canceled and the hero Restocks instead.
When the Overlord is purchasing threat during his turn can he only purchase 1 threat per turn or can he purchase as much threat as he is willing to spend?
I assume you mean Treachery, not threat. The OL purchases treachery upgrades during his weekly turn but gets threat each turn (which is not purchased) during a dungeon.
The OL may only buy one point of treachery as his weekly upgrade.