I never thought about the relationship between the brain sex theory and intersexuality, but that definition of intersex does seem very compatible with being trans. To me, it appears that the trans discourse is leaving the realm of biology to a greater an greater extent, but it would certainly be more constructive it ended up focusing on the issues you mention here. Perhaps formally separating the concepts of trans-gender and trans-sexual would be beneficial- such that we could deal with the ambiguity created by term “gender,” as you discussed.

Thanks for writing out this well-researched post- I think I understand a little better why my gender is the way it is