My beef with virtual reality environments reflects on my regular beef with bar RP in general. Spatial awareness adds to the general confusion of 'who is located where?' issues, tiny cliques of people huddled together ignoring everyone else, new people teleporting about with enhanced-hearing techniques, and pilots in space multi-tasking piloting a starship and coordinating a virtual body. The cleanliness of a comms channel means people come in and verbally interact without having to worry about that kind of stuff.
As for exclusivity, I think anyone should be able to join the channel and those who participate should behave respectfully in regard to the values of Amarrian culture. It's not meant to be a 'behind closed doors' environment where the Amarr let their hair down and have orgies, but they should be able to voice their ideas without being berated by heretics and non-believers. It should also be a place to convert those who are interested, and I think making the channel invite-only kinda destroys any chance of that.