Hi - no worries :)
In WP Symposium, you should have a look at the so-called forum categories, to display them depending on membership. As far the widgets I'm not sure but I think they respect these settings.
If you intend to consider the forum as a whole, you could play with a role management plugin to display the page itself, and plugins like Dynamic Widgets to display widgets, depending on user role. Similarly with WPS Toolbar, you may display a custom menu in the Toolbar, to show a link to the forum or not.
I know you closed the topic, but I thought this could bring some light.