The attack helicopter statement is a little joke, it references how people say they're genderqueer and so forth, and made by meme lovers and right wing people like louder with crowder and milo.
Also there's a good term for those, they're called hermaphrodites. Also it's not it's own biological sex, is a birth defect. I know cultural and social is not the same as biological, but almost all people who are born don't mind being called by their biological gender. It's also proven that being trangender is a brain dysfunction, one study shown here. Johns Hopkins Psychiatrist: Transgender is ‘Mental Disorder;' Sex Change ‘Biologically Impossible’
Hermaphrodite doesn't cover all the people covered by the term intersex. And the term intersex is the current medical term for it.
Almost, yes.
Gender dysphoria is a disorder best treated through hormone replacement therapy and in some cases gender reassignment surgery.