Prof,
You have been doing a great job so your decision is what is best. If you start voting and all that jazz it can only come back to bite you in the ass. I mean we all have different views here though we share many common views. But a voting system sounds a bit scarey like things we have all seen not so long ago and its hard to please everyone …. all in all I believe in what you have done so far and would rather not be one that has to make these decsions when the you already do such great work. Its your forums and I know that you will make the best decisions for what we need here.
I do agree that some will not make posts in public areas but well that is there choice, but even occasional posts in public which we all do here whether its a opinion or a helping tip is what is needed. I have seen all of us here with access in the private areas do this for newbies or just people in need of help which is what’s needed for your site to grow.