In some cases, I do giveaways with multiple draws - sometimes this can take a while so it would be nice if it would be possible to re-open a raffle (at least for any new users) I wouldn't want people who already have tickets in to be able to remove tickets, would just like for new people to be able to join if a giveaway has been going on for 30 mins or so. The other option would just be to implement this only for keyword raffles if it is too difficult to allow new users to join but not allow people to take their tickets out.
An alternative would be to allow for a partial ticket refund when finished with a rafflle - such that if you didn't get drawn, you get a certain % of your tickets back (user-settable).
I wouldn't say either of these are super high priority, just things I've run into that would be neat to have =D
