“This thing is ambitious and compelling” says people selling you the thing.

They mean being able to group several windows together as tabs, rather than tabs implemented in specific applications.

“Scrolling moves the content” means the content moves opposite of the direction you scroll a la smartphones and tablets, i.e. scrolling up will make content move down.

Nah that would be blatantly obvious. Elon doesn’t go more than very obvious.

Because he doesn’t care about user control if it means people can choose not to see his tweets.