1. Don't look at ERA for pitchers. Osuna is one of the top closers in the game, and he's only 23. He does however have some anxiety issues (which may or may not be related to a very "complicated" off field life). I would probably put Chapman, Kimbrel, Jansen, Miller in a top tier, with guys like Davis, Britton, Osuna, Giles, Allen in the next tier. You basically traded for a pitcher equal to Giles, but with an extra year of control and a fresh start for both. As far as I know, there's been no clubhouse issues with Osuna at all. Everyone seems to really like him.
2. We don't know exactly what was on tape. There's reports all the way from it being fairly minor to shocking, although I think if it was the latter MLB would have suspended him much longer.