Re: dealing with uke from hell
Noting that this is an UFH, and not a compassionate senpai that is teaching and guiding through exposing openings or incorrect angles, etc., in a kohai's technique, adapting the technique is never a good idea in a Kihon Waza setting. As others have said, the UFH will just become (now) openly egocentric and express that lack of virtue via anger, insult, or even violence. This is especially true when the nage does not have the institutional support of the ranking system and/or federation title.
Over the years, in my contact with UFHs, I've done the smiles, and the reversals, and the atemi, etc., but looking back now, I see that what is really going on is a dojo being ran by a sensei/dojocho that either doesn't know the right thing to do or that does not have the courage and integrity to do the right thing. That is the only way you get a UFH to reguarly appear on the mat in a Kihon Waza oriented class.
If you really want a solution to this problem, I would leave the dojo and find a more cultivated teacher.