Alan, I contemplated the exact same thing. I thought about making the recommendation to only allow members in good standing access to the website.
Then I reconsidered.
I believe that there is a wealth of knowledge here that should be available to anyone. I also believe that allowing the general public to register and be a part of the discussions is inviting to others and a good thing. Sharing our weather data and site information also improves the pilot and their experience.
For those reasons my position would be to keep the forum open and monitor the posts versus a closed forum.