I would be in favor of all but possibly one of the suggestions listed above, depending. If the moderator-only accessed areas means what i think it means, then I don't like this one idea, because it defeats the whole purpose of having such an area.
As for fees, well, I'm an awful businesswoman, but how much a year would it cost to run and maintain a special, ad-free forum? That would be the only way I could mathematically figure what a fair subscription would be, or even if it would be worth offering such a thing. That is, if I were smart enough to do the math!
OH! More picture space would be nice, too!