There's only ever been a handful of narcissists here at any given time. As it is, I'm pretty sure I'm the only one here who is consistently watching these boards. That said, I am an atypical case. I'm a malignant narcissist and I've always had an unusual amount of insight into myself and why I do the things I do.
A lot of people make the same mistake you did about misunderstanding the purpose of this subforum, it's not a big deal, at least not to me. Some discussions started here by 'nons" as we affectionately call them have actually been downright fascinating. I think people here get upset when nons come in and start ranting about how all narcissists (and psychopaths) are inherently evil. For some reason most people are sensitive to the word evil. I'm not one of those people, I openly refer to myself as such because evil is a better word to describe both my actions and who I actually am better than a label of NPD. Not all narcissists are evil, they just do evil things. I am an evil narcissist that of course does evil things, and it surprises people every time when I decide to do something profoundly good.
Anyways I don't want to ramble on about myself too much, but provided that you're reasonably respectful and genuinely want to understand the narcissist in your life, I don't see any reason why you can't post here. Some questions are best answered by people who suffer from the condition themselves.
Edit: added something.