That type of behavior has not been tolerated in any school I have ever attended. The offending white belt is quickly spoken to by sensei and if their behavior is not corrected they are told they will not be returning.
Need a laugh? Check this out. Make sure you go all the way down the page to see how to go to the bathroom in your gi. http://www.geocities.com/antsummers/secrets.htm
Spinning back kicks were very difficult to master. And I had more trouble than most. Like and kick, or skill for that matter, it takes a lot of practice.
I think everyone finds a kick that suits them best. I have seen some do exceptional side kicks. I have also seen some to some horrid side kicks. We are all different. The kick I have best control with, speed and accuracy doing is a round house.
I had a sparring partner I used to meet at the "Y". That was until they moved out of town. We didn't really point spar we just sort of did light contact and had fun with it.