I'd by and large agree with you, Tom: women wearing (ordinary) male clothing is not seen as extraordinary today - only 80 years ago a woman wearing trousers, not to speak of´a male-style jacket, was a political statement, and could even be seen as a denial of her own femininity.

I've been to a few parties with dykes and drag kings who were into uniform stuff and male costumes (police, cowboys etc) and it was obvious that some of them didn't just see it as a roleplay thing but also felt sexually thrilled and empowered by wearing police shirts and caps, prop guns, loose beards and the like. So I think the element of sexual identity can't be denied in crossdressing, and also there's no hard-and-fast line dividing sexual role and physical role (here: the wish to be, in your body, the sex which you feel, genderwise, you belong to).