I mean, in addition to McEnroe's public tantrums, didn't he kind of require Tatum O'Neal to give up acting and the reason for their divorce was that she decided to accept a role?

I think they figured, let's hire a big putz to play the biggest tennis putz ever!
@1) No, Tatum was (maybe is) hooked on smack for her entire adult life and could not hold down a job. She couldn't raise her kids she was so strung out. Finally he gave up loving a junkie. Not that he isn't a big putz, tho.

ASIDE: MacEnroe tried his pants off to be a rock star once he became tennis famous. He was convinced he was as gifted a guitarist as tennis player. That is your laugh for the day.

McEnroe was an absolute psychopath back in the day. A terror. Everyone in tennis feared his outbursts and too bad the actor/film didn't capture that aura.