Agree he's a weird dude.
Agree Berry is probably liked as a person and maybe even as a coach (I've heard he's a good dude, actually), but not as a play caller. He would probably be best served as a position coach and not a coordinator.
I don't get the impression he's a quick thinker, and I think he likes to default to rush 4 and drop 7 into zone. That's a Rod Marinelli Tampa 2 thing, and that's where his true roots are.

As for Jaire, I don't think they could trade him if they wanted to, which they don't.
He'd be the largest non QB cap hit if he were traded or cut, and he's owed a lot of money still. They'll need to restructure some of his money next season to get cap space to do anything outside of signing their draft picks.
Eating his contract by trading him is not a good idea, especially when you have the David Bakhtiari and Aaron Jones contracts to consider.

Jaire probably needs a fresh start next season and a new DC... my guess is he comes in re-energized and with (according to him) an all new Jaire attitude and plays up to his reputation. Injuries have bothered him all year, but even early in the season he wasn't that great. He wasn't All-Pro, that's for sure. CBs usually don't have long windows of greatness, he has work to do to reach that level again.