I think the proposed changes are pretty good. Keeping ad threads cleaner and making a more obvious divide between constructive reviews and throwing mud seems like the way to go to solve a number of issues that keep coming up.
For the rest, though? I think it's fine as it is.
While some people like @Paris don't seem to want to accept it, the bottom line is this: if this place shut down, someone would make a new one. If that one shut down, someone else would make a new one. If that new place shut down, you get the idea. This isn't up for debate, we've seen it happen already.
People need an outlet to voice their frustrations with the hobby, warranted or not. There'll always be abusive admins, abusive players, and this place existing doesn't change that. If they weren't being disruptive here, they'd be disruptive somewhere else. The behaviors that make this place "undesirable" are behaviors you'd continue seeing even if we closed shop. You'd see it on whatever new forums were made to bitch and on the games themselves. You'd see it in Livejournal communities like Bad_RPers_Suck. Maybe someone'd create /r/WORA.
I'd rather people be assholes here than on the games/at the players they're being assholes about. You can ignore this place, but you can't ignore a MUSH you play on without making the decision not to play on it. In fact I'd say a majority of players in the hobby do a very good job of ignoring - or not knowing - this place even exists. Because we don't advertise. Because the hog pit requires signing up for rather unintuitively, and someone who found this place by accident wouldn't know to look for it.
If you can see the hog pit - the toxic part of this place - you made a conscious choice to see it. If you don't like what you see, you can leave the hog pit group and never have to care again. If someone keeps nagging you, your staff, your players, on public or private channels, to "check out what these jerks are saying about a player/a game" you can tell them to stop bringing it up. Being obsessed about what people say here, if you don't like it, isn't healthy, so here's a novel idea: just stop looking at it.
MSB is the vocal minority in every sense of the word. Better everything that it entails be happening here than elsewhere.