In terms of monetization, I'd also consider tokenizing likes or like ratios or something along those lines.... the same way you can skip the boring "farming" aspects of a video game by just buying "credits" instead. Leveling up should cost something; time or money. It's game development 101 these days.
This forum is not a game. You are thinking inside a box of P2P that does not apply to online forums. There are other trading forums out there that do this, such as "giving a special title" for a certain amount of money.
I'm talking about a monthly subscription to be able to engage with a feature of the site, namely the chat thingy, not to buy
Tchotchkes
to you 
