Of course. But if someone says "that's so gay" no one today thinks that means "that is so happy." The meaning has been changed.
I agree! Who decides what they are? You . . . or them? How about a man who looks androgynous? Should you be able to decide "hey, you look like a chick - head to the women's room or I am calling the cops!" I'd argue that it is up to her, even if you think they are a woman (and even if they have XX chromosomes, as happens in AIS.)
How about a trans woman who is transitioning, living as a woman, but who hasn't had surgery yet? How about if they have had top but not bottom surgery, and are wanting to wait a bit before the bottom surgery? Who decides what gender they are? Again, I would argue that they do.
Nope. Because there is an actual, medical difference between a vaccinated and an unvaccinated person. There is no such clear difference in transgender people. (Or even in AIS people.)
Again, it's like a woman (or man) changing their name after marriage. It's up to them what they want their name to be. There is no "medical reason" for them to change their name; they just want to, and most people do not have a problem with that. They can, of course, misuse that and try to use the name change to cover up a criminal past or something. But we would not say "NO MORE NAME CHANGES WHEN YOU GET MARRIED!" just because .01% of people who change their names do so for nefarious reasons.