Being a teacher I know from experience that at times you shout. However, this should never be a regular occurence, and never should it be acceptable for children to shout at teachers. As for the taking of lunch that is wrong, and the children should be taught that this is an unacceptable way to behaviour.
I have worked in a school with a total no. of 40 kids and I loved it, it was alot different from anything I had ever done before, however I think personally I would only send my children there till yr3 and then move them to a bigger school.