Now, the whole set of questions. be aware, as I hinted, I'm in my 40's, a lot of my perceptions are not going to be in line with the teen/20-something generation's views
There is no hiding the fact that being trans is an abnormality - it is a dysphoria. Ever looked in a mirror and felt "fuck, I'm too fat/thin/spotty/short/tall, I hate myself"? well imagine if every time you looked in the mirror you felt that times 1000, thought "I'm not this person. I don't want these tits/dick/stubble", or if every month you bled it felt like it was something twisting you inside that you didn't want. Every time you went out with a group of people, you were thinking "I not like these guys", or the likes. Well, that's what being trans is, at its root. Its the feeling that you are in the wrong body, and yes, that fucks them up in the head, often for years before they get listened to.
And most transpeople have a "I'm not a guy/girl" feeling even as kids.
My ex's son, I knew when they were, to everyone's perception over the years a child to young teenager, a blonde girl with long hair who wore pink all the time. And what he said, when we were chatting in the bar a few years back was "I used to think if I wore all the girly pink, and had the long hair, and played with the dolls, then somehow, I'd become like the other girls. But it felt like I was pretending to be it, every single day". They were about 16 and they went "this isnt me", and being able to live their life in a way they were comfortable with, changed their mental health completely, from wanting to stop existing, to being able to live a life they wanted.
So, when you talk about "grooming" and all that shit, the reality is many transpeople are talking of their own experience growing up, trapped in that horrible place of not fitting in, and knowing others are there, trying to find their own expression, and how those who say "I'm not a boy/girl" when kids should be listened to, for their mental health.