Nice idea, needs some thinking beyond the box. So not for these guys.
A social forum for porn industry and porn consumers.
Access for industry restricted to people who can prove they're in the business.
Access for consumers from porn sites at first and let it build. Keep outright spamming to a minimum. More about "What I did today" and "What do you think of my work" from industry personnel and then consumers thoughts, keep the trolls at bay.
Advertising is 2 tier, sites can advertise and industry can.
As for this place becoming a social forum. Most would have to get a life worth talking about first, I probably have more fun than they do.