1. Allow creating tables with undo disabled. -- I hate it when my opponent does not play well and asks for an undo, if I deny, my opponent starts to revenge by playing slowly or saying bad things.
2. Shorten the time that a player needs to wait before able to resign idle opponent. -- Some players disconnect right after it has become clear that there is no hope to win.
3. Improve the shuffling! -- Definitely there is a very strong correlation between successive draws in the current implementation.