fighting a loosing battle i think!!!! the way i see, as long as nothing gets out of hand, there's nothing you can really do other than ban all advertising? as soon as you ask for advise and the response is "see how i did it here, or check my site" there is nothing you can do.
you're right about bad press, but some of the sites don't need any help with that, there are a few really bad shirts floating about your site, and a fair bit of bad advice too.
in my experince, forums seem to police themselves most of the time. if you act like a pri*k most people will ignore you and the kind of people who log onto every forum they come across just to post an ad for their site rarely come back.
all in all this site is providing possitive advice and you have a community of manufacturers, novice buisness men, designers. thats a good thing. if you start to ban individuals for mentioning their own business or a service they can provide, you'll loose the know how and people will look else where.
lets get back to shirts rather than this un-resolvable forum tennis!!!