I actually like this idea.
But NYC/DC isn't really a good group. We had a thread that was like NY/PA/NJ or something like that. Including DC is okish, but specifying NYC excludes so many of us. Like that's the closest to me of the groups you gave and it's a pretty good distance away even though I'm in New York.
But as far as this idea, us Northest US scummers are pretty bad at organizing ourselves but always talking about doing things and I think having a subforum might somewhat help that.
I'd like to start a mafiascum pool league on pogo. See this thread for details:
If you are interested, please post in the thread. Won't start the league unless I see interest.