*reads more then half of the thread*
Loneliness is a nasty thing. I know from experience. I'm 20 and I still feel lonely. All because I'm different, shy and have very different opinions on life and society in general. Always have been and always will be like that. I've also noticed that people can pick on you, just because you are you.
About the bullying, there is nothing to be done about it. When you start hitting during schooltime, it's usually your fault despite anything they have done before to you. I don't have any trust in how schools are handling this problem but sadly, teachers keep being the best shot you have at getting to the bullies and stopping them.
Ignoring bullying behavior is hard because bullies are usually attacking the person who you are, not just because you are 'different'. Don't know why, but it was usually the case for me. The fact that they are punishing you for who you are is what is the stinger here.
@Everyone saying that he should be himself: We don't know him. For all we know he's being himself all the time but they still pick on him and prefer to hang out with others. It sucks, but there is nothing that can be done about this unless he plans to go on 'survival mode' and stops being himself to pleasure others.