I have several TG friends and they do label themselves as TG online (every one of them sticking the TG or M2F after their names / aliases). but when in public, yes, prefer to be called "she".
Everything else you've stated I agree with. Especially love the last comment, hun. I remember as a kid when I beat Metroid and saw it was a she my friend and I both went "wait, what?" And then when we learned the Justin Bailey code... HAH! It blew our minds.
You've got me thinking now, though... how would a TG love scene work in inquisition.... bet the masses would FLIP! My elven female was fully nude with Blackwall's love making... the media would have a field day if she had a package between her legs in that scene, I bet!
I was so disappointed in Inquisition- I essentially
never roll a female, or a caster, or an elf, and decided to be different this time around and play a female elven caster. And then neither Cassandra OR Dorian would flirt with me cause I wasn't a guy.

Drat! Who knew I'd get screwed over because Cassandra isn't gay, and Dorian is? Much disappoint! I'm rolling a dude when I start it again! XD
But yeah, I mostly meant in 'public', or typical game situations. It's not really believable for someone to, say, introduce themselves with the preface of being gay, or transgender, or anything like that, it just isn't something that would typically come up in a conversational situation unless it was specifically about that, you know? So unless you're shoehorning it in for the effect of -
this character is GAY- in your game, or the game specifically has a romantic scene, it just doesn't seem like something that's needed to openly state in your game. Hence it being more a 'trivia' style thing, rather then a necessary element. To me, that sort of thing seems like the normal kind of subtle things you'd encounter in real life- and that sort of thing doesn't show up as much in games.
I guess what I'm trying to say is, that in most games it seems like the only way being transgender, gay, bi, etc would be noticeable in the slightest would be if the character were ridiculously flamboyant about it- romantic/sexual games as an obvious exception. I mean, most games don't focus on that aspect of character, it's more like 'princess kidnapped, must rescue!' which doesn't necessarily imply that you're doing the rescuing and then intending to shag said princess. You could just be doing something nice, or because it's the right thing to do, or your a badass knight or the like. And I realize that there ARE gay/trangender/bi/whatever people that are very flamboyant but unless it were done very well (kind of like Dorian from Inquisition, flamboyant, but not rudely so) a flamboyant character might easily come off as being a mockery of said group of people in a media situation. Seems a prickly patch to cross with how sensitive people are- wouldn't want it to come off as an unintended insult! I bet a lot of the larger game producers like EA and such are hesitant to attempt because of that...