Dungeons: No fast respawn while you are in. It destroys the believability of the world to go into a dungeon, kill everything and when you are on your way out (nothing else, just going back where you came)... it's full again. I mean... HUH? Respawn when you re-enter is fine. If you want to have a respawn, you can spawn only a few monsters for the way out.
Yeah, right, just because you were too smart to choose Normal/Hard diff and not Easy one, all munchkins must leave and enter into dungeon again. EVERY time. Great.