The kendo group i train with does those techniques actually. My sensei trained in Haga Dojo in Tokyo and they are a pre-war kendo dojo. Choking out your opponent, ripping off their men, foot sweeps, throws, etc are just a part of are normal practice. Its pretty rough sometimes, but its not really painful to get thrown around actually. Its more aggravating that you got choked out or had your men pulled off. But that just makes you train harder so it doesnt happen again. We all give as good as we get and have a blast doing it!