One further update on this. I think I've finally fixed the issue with the wiki subdomain pointing to one of my other sites. Unfortunately, the wiki is broken at the moment (not sure what broke it), but am planning to work on it some over the coming days.

I'm still looking into the Wikia idea as well. Right now I do see one possible issue. The license I'm currently using for the wiki doesn't allow people to use the text or other info from the wiki for commercial purposes. I chose this license because I didn't like the idea of people making money off things that we make available for free and that we aren't making any money off of.

I still need to look into it more to see what sorts of extensions they do/don't allow and such.