Sorry, but in the modern world the answer to all your questions is Yes.
Anybody who questions his self-identification is denounced and ostracized. Possibly soon to be criminalized.
There are, BTW, a host of types of body dysphoria. There are people who believe they’re “really” another species. Angel, demon, elf, orc. Or Popeye the Sailor Man.
http://en.wikipedia.org/wiki/Otherkin
There are people who firmly believe their leg (or whatever) doesn’t belong to them and needs to be removed. They go to amazing lengths to get it amputated.
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=body+dysphoria
We all pretty much recognize these as mental illnesses, at least the second variety. But somehow drag sex into the situation and we lose our ability to think logically.
You’re right, of course.
I saw a documentary once about the people who don’t want their limbs.
Many little children identify as their pets or as TV characters. They’ll adopt the mannerisms and everything. Eventually, they grow out of that phase. But I guess some never do, especially if the behavior is reinforced somehow.
Many years ago, I was listening to the Dr. Laura radio show one day, and a crossdresser called in. I’m not a big fan of Dr. Laura, but I’ll never forget what she told him. She said: “As a woman, I wear dresses sometimes. But I don’t NEED to wear dresses. You do understand the difference, right?”