It is hard to answear the question without seeing the match. I believe head tapping and head movement are great set ups. Totally up to the ref on what is to hard.

As far as biting...Jake got bit twice in the same match. After the match we went up to the coach, explained that we weren't upset but thought the biting needed to be brought to his attention. The coach spoke with the kid as did his mother. I thought it was handled well. I think the key is too not over-react. Most parents and coaches will handle it appropriately if it is brought to their attention in a calm manner.