All of this still happens, you just have to look for them. Kids dance to whatever they want, have a look at any social media, they probably dance more than ever before.

Kids don't go to mosh pits but these still happen. There are raves year round all around the world, from electro to death metal

Maybe you got too old and/or just plain disconnected from the new youth culture(s), it doesn't mean it doesn't exist

Yes.

Various.

Yes.

Whether it is more or less, like say 20 years ago, I could not tell, but I would say it is more divers today. Less strict defined scenes.