See ... I half get what you are saying, *kim. 
?A transwoman has had surgery. She looks, sounds and can pass for a female. She gives in her passport / driving license / ID - gender = male. What would happen??
Given photo ID exists, does it need to be an issue? Plenty of non-trans people look like the other sex, or their sex isn?t readily apparent. Perhaps you?re right ID doesn?t need to have the person?s sex on it (that?d be much my preferred option). Maybe it?d be best just to make people stop questioning how others look.
But I?m a bit confused here. You seem to be saying here it?s purely an issue of convenience (so, I guess, one of those accommodations to the patriarchy). But ? forgive me, I don?t want to nitpick but I feel like this is the heart of the issue ? you also seem to be saying it?s an emotional issue. I couldn?t help noticing on another thread we?re both on, you were sad when someone thought you were a ?he? not a ?she?. Given we are on the internet, this can?t be to do with how you ?look? or ?sound?, I would think? And you were saying earlier how much you hate masculinity and being identified as a male. So ? I?m sorry, I don?t really get how come you?re now telling me it?s all simple convenience, just to do with fitting into a world that isn?t ok with people who look a bit different from what our gender expectations tell us they ought to look like?
?The law - well if you want surgery, you do not need to be recognised as a woman. You are supposed to have changed your ID to a female name, had hormones and undergone RLE (real life experience - and I know you cannot experience living as a woman, you are experiencing living as trans). Then they will give surgery if they feel you are psychologically ready and you hate your body.?
Do you know why the law is as it is, then? It sounds like you are saying there?s really no need for it, they might as well not have redefined what ?woman? and ?she? mean ? but they have. Is this a big issue for transpeople too?
What I don?t get is, we?re told (inc. on MN) that it is so unutterably rude and illegal to question whether a transperson is in any way different from a person born into the sex they now legally are ? why?