Variety reports that a number of parties have approached Sony if NBC did not pick up the show. I would guess Hulu and Comedy Central are the front runners since they own the digital and syndication rights respectively.

Amy Poehler is the reason why NBC did not cancel P&R. NBC wants to keep her happy so she will agree to co-host The Golden Globes with Tina Fey for the next decade.

I will agree with you that Go On was funnier than season 4 of Community. But Dan Harmon's season 5 of Community trumps whatever a season 2 of Go On could have mustered up. The first 6 episodes of season 5 were brilliant.

We will at least see a Community movie via Kickstarter. Dan Harmon himself have said that a movie will be made even if it has to be film in his basement.