In my opinion, opening up Inside Scoop is a good idea. However, I'd personally change the name; it's not much of a scoop if anyone can read it. SDS suggested 'The Outside Scoop' on IRC; I'd rather the word 'scoop' be removed entirely, though. How about 'Coffee Lounge'?
I'm pretty sure it should be possible to only make certain threads public. I'll set up a thread in IS (CL) so we can decide which we should release.
Finally, we don't have to grant everyone posting privileges, right? IS (CL) can stay exclusive to badged users in terms of posting rights. It's still the staff's job to run the site, but ordinary users should have the right to be able to see proposed changes that may affect them.