I am sure this has been discussed and you probably have good reasons for nit having done it.
I often see posters post items in Penny who could have posted in Inner Thoughts. A reason often given is that "it's easier"; they know its not ideal but they make the tradeoff because it is easier. I presume this has to do with scrolling. Why not move the Banquet Room to the top and hide it for non-members? At least this way most traffic would go to the more private areas. Non-members would not see it and so would not realize it wasn't there. It would require minor one-time user re-education and should be technically reasonably simple.
It would take a small amount effort to makes things public, which means users would tend to err on the side of caution.