Re: dealing with uke from hell
One option is to do the technique quicker than what the UFH is expecting (not giving them time to resist) or if the is a kensetsu element crank it a little harder.
It reminds me of the time when I was still a mudansha but the senior student and we had a guy that was an UFH on purpose. Me and the next highest ranked student knew we should handle the situation so our Sensei could concentrate on teaching and not any petty issues. What we did is talk to our U.S. Technical Director when we were at a training session at his dojo and explained the situation and how we didn't want to burden our Sensei with having to deal with this aspect of dojo logistics. He just smiled and said that was good (that we were trying to take care of it as best as possible) then he proceeded to tell us that "sometimes to make a (flowering) tree bloom you have to trim/prune a few branches." So basically, said you need to take the Barney Fife approach and "Nip it in the Bud!"