The wiki is maintained as a resource by all those involved with ToME who wish to contribute. The wiki is easy to maintain, and that's really the idea, I think.
The forum is great for discussion. It has an automatic post and reply structure, which is far simpler than trying to maintain verbose threads on the wiki, and this avoids the problem of editing clashes, and other simple mistakes which can mess up formatting.
However, what the forum can't do is keep a whole load of information in one place, and provide a concise reference that people can look to if they need to find specific (or even general) information. It simply isn't designed to do so. And that's why the wiki was made in the first place. You can have lists, tables, tables of contents, anchors, all kinds of naviagtional aids and a structure: you can do so many things to make information more findable than trying to look through a pages long FAQ on a monotonous forum thread.
Certainly if people want their questions answered, they post here. Or if they want to enlarge the discussion of a topic already covered they can post here. Or even if they just want to talk to people. However, to my mind, creating a thread specifically as "a centralized place where people can come and have their questions answered" is simply trying to condense the whole forum. "FAQ" is a very loose term, and can cover anything (in the area of spoilers) from to . If you try to merge all of that, you're effectively going to be duplicating the entire on the wiki into one forum thread.
By all means link to the wiki. A higher profile for it would be useful, since then newcomers would actually know of it's existence, and there would be an added incentive to bother going there to find information, rather than just creating yet another "what are the sentient weapons realms?" or "what can I wish for?".
If you want advice on any of those kind of things, or think there is something more to say on the topics, then by all means expand the discussion here. However, if it's been discussed before here there's simply no point in reguritating the old information...
--> look it up: search.php
And if you know that the information is readily available on the wiki (or even might be: it almost certainly is)...
--> go there: http://wiki.t-o-m-e.net