You have a truely rare problem. Most people don't think about thier horse enough but I think you think way too much. You can't spend so much time disecting everything your horse does that you don't get anything done. If he tries to bite you then deal with it but then move on.
However, a while back (when I was looking for someone to put miles on him) I realized that I'm probably throwing him off balance...my left leg is a quarter of an inch longer than my right, and I'm left handed to begin with. Then while I was watching Kristen work with him, I realized I was clenching my jaw and hunching my shoulders a little bit. I've known for a long time that his trot makes me tense, along with the above observations on my timing and my forgiveness.
Ever so slowly I'm learning