You make good points and clearly its not always simple. If she has defined sex organs, regardless of the testosterone or estrogen production, that should determine where he / or she competes. The ultimate goal of a competitive event is not to allow everyone to participate. It is to determine excellence. If he/she has both sex organs, competition should be with the most challenging group rather than the group he / she would like to compete with or associates with. Certainly not an easy call but one that is true to the goal of competition.