The forum isn’t perfect but it isn’t insecure.
We chose to build our own forum for many reasons. The most important one being that it’s easy to understand and implement features quickly. I rather not waste time writing hook functions and painfully trying to integrate your GHI accounts into a forum. Trying to adapt a forum software into your existing layout is not an simple task. The forum will then look similar to other forums in a cookie cutter sort of way. I don’t consider that professional. Having something look familiar is both good and bad. TinyCLR is going for playful feel!
Private messaging takes away from the community by making helpful conversations private. If you really need to communicate one on one you can talk over IM or email. I plan to put in a form so you can message a member with your private contact details through their profile page.
Everyone at GHI uses the forum as much as our users if not more. We realize that the forum lacks things, but we will be transforming it into everything you’ve mentioned (for the most part) soon. Patience is a virtue!
P.S. I don’t play World of Warcraft