I'd say forget the fee idea, I honestly like the structure atm, as people in a higher level have worked and earnt the right to be there. If you change it to a fee based structure like WF people will be better then you just because they can afford the fee, and tbh i'd personally leave both because of that, and because I couldn't afford the fee.
I find BHW a place where everyone is willing to help, and treat everyone else as equals and not condescending.
I agree with that Diamond Dave, you do have a PM problem, however there are ways to solve this, the easiest of which would be to set up a ticket system, so that anything forum related is dealt with by tickets rather then by PM people. This would also improve the service as a ticket can be picked up by any member of the admin team online at that time.
Just my two-cents.