I think waiting 5 days to repeat a duel is way too long. Now I find myself not being able to duel anybody for 5 days...
Besides, I don't agree with Euronymous saying that with this current system only most active players will stay on top. Once you hit the top you just have to duel your immediate opponents, beat them, and keep your position. Besides, as it is now, those players on 1-5 positions can only duel around 7 people I think, so if somebody is 3rd and you are second, is not like the 3rd one can duel 20 players that you CANNOT... 6-7 duels every 3 days don't seem a lot, do they?
Cancelling duels after there's more than 180 points difference is a MUST.