Something cannot be a disorder unless it causes harm. Things that are not disorders and are out of the ordinary can be considered adaptations and can be advantageous.
Harm to whom? Many things can cause harm to oneself (socially, at least) without harming anyone else. Being odd about your pronouns is one of those things.
Pedantically, there is no such thing as "correct" or "incorrect" English as there is no standards body that dictates such rules. You can verb any word you want and people will understand what you mean.
You don't have to read the article if it doesn't meet your muster. Why bother caring?
Who's to say it's "incorrect English?" You clearly understood what was said. This person's identity seems like the least interesting and most irrelevant part of this discussion.
