Having this many different forums really breaks up the sense of community. I suggest reducing the number and then adding more when you need them, if ever. I suspect that one reason why people use the mailing list instead of forums is the you get everything in one place, and you meet everyone who has posted whenever you download the list, which creates a sense of community. Ideally, the forums could serve to organize the messages, but not break up the sense of community.
Here's my suggestions:
Combine 'Music made with Audiomulch' and 'Performance...'
Combine Mac and PC plugins into one 'Plugins' forum
Combine 'Support...' and 'Bugs and Issues'
This is just off the top of my head.