I don't recall exactly how CO was set up. TV worked for a long time, and it was never "open." I don't think j00 is using either of those as a model.
I'd prefer the model where everything is closed except a free posting sub that's visible to guests, where they can also post. It should be heavily modded, text only (no images, vids or hotlinks permitted) and maybe even word filtered, and the same anti-spammer settings as the rest of the forum.