Sanctuary was a terrible mental health facility. Whether or not King and DC realized it, I don't know.
Batman, Superman and Wonder Woman came off as assholes for setting this whole facility up and I'm mad that they haven't been called out more.
Gnarrk seemed to be getting better.
It wasn't supposed to be a good thing, it was to drive home the fact that Wally was totally unhinged.
Because the writers said so. No hero SHOULD ever go back there.
I have no idea. King has a trauma fetish. He knows how to traumatize characters but doesn't know how to have them overcome their issue.