They do not block it, I currently host several servers with gameservers.com that run B3 on from a remote box using FTP.
Not yet, but remember that they can change it at any time, especially if they see a way to make money. With their exclusivity, they make the rules, and if you don't like it, tough luck.
Not trying to be a pessimist, just a realist. Money is the motivater for alot of things...
*Via my HTC EvO 4G*