Re: dealing with uke from hell
It might be worth discussing how not to BE the uke from hell. In my own ukemi practice, I give Shite a lot of feedback, so I am careful to be benevolent. Most Aikidoka probably do the same thing in their own way- not verbal feedback, but resisting in the right way and yielding in ways that seem to encourage proper application. If a pin is weak, I will give a little wiggle of the elbow or raise my shoulder enough for them to notice.
I absolutely take some dives, but will do a walkaway if a point can be made by it. They are throws, after all. Resisting wristlocks can get you in trouble if you have a very impatient Shite, but I will give them similar advice to what I posted above (on the Q.T.) and these two, if they ask:
#1. "We only get better at what we practice correctly." (credentialed) Grand Master, Dr. Nam K. Hyong.
#2. "Smooth is fast." Joe Thambu Shihan. So slow down and do it right.