Your Sensei does beat people up! He also has x-ray vision and can leap tall buildings in a single bound.
I have had the chance to meet Mori sensei and was quite honestly surprised by how gentle his manner is. I really was surprised to then see him perform his kata and how much power he puts into his techniques.
I wouldn't worry too much about others peoples corcerns about his methods. You've just stumbled across the old school -v- new school arguement, martial -v- safety. Personally I don't mind being thrown like that occasioally but I am not interesting in joining the riot police either so I would be concerned about the mileage I would get out of that sort of training. But what ever floats your boat. I am very confident that Mori sensei is not abusive to his students.