I think we should try to give opponents the same respect they would get OTB, where this behavior probably wouldn't be acceptable. Clocks have nothing to do with what chess is really about in my opinion, except in bullet chess, but that isn't really chess is it?
The following thread is very relevant to this one.
http://www.chess.com/forum/view/general/rare-otb-chess-experience
4. Yes, especially if he played a good game. QvQ is a theoretical draw anyways, and I would feel that he deserves the draw.
Both of you guys ended up with an equally good position... there is one thing you are missing -- your opponent has used more time! If he used more time to get an equal position, has he really played as well as you? Why not punish him for it? If there was any amount of increment, I might take the draw, but that would only be if I didn't believe I could exploit my opponent's lack of time (because the position might be simple enough), not because I feel like I have to show respect.
If my opponent uses more time than me, and I don't try to use that to my advantage, then it's like I've given my opponent a time handicap; I'd be making things unfair for myself.
All in all, getting to King and Queen with 5 minutes left on the clock is harder than getting to King and Queen with 20 seconds on the clock. In zero increment, that's as bad as being down a queen. I dislike zero increment (this scenario being one of the reasons), but if I happen to be playing such a game, then I will adjust my strategies accordingly. If you look at the top blitz players, you'll notice that they are able to get good positions yet still have plenty of time, even with no increment! Effective time management is a skill.