I've got some experience moderating popular fora (I cringe everytime I see "forums"), and I have an opinion, which I consistently over-value.

Moderating is an unappreciated art. It's extremely difficult to seem welcoming or helpfull as you delete someone's thread/post/whatever or limit their potential actions, regardless of intent. It's an incredibly fine line to walk, and you're going to create nearly as many problems as you solve with heavy-handed moderation.

Limiting the user's ability to create new threads, while initially attractive, sets a bad tone. It treats everyone as a potential troublemaker, which can very quickly become a self-fufilling prophecy.

As others have mentioned, the search function leaves much to be desired. I have faced nearly insurmountable difficulties in finding threads I know to have existed. This is compounded by how the topics are, IMO, overly divided and less than concise about their intended content.

My suggestion would be to add a static link to the wiki at the top of the page, along with a friendly reminder to use the search function before posting new topics. Such a reminder and link could be shown directly to the user and require confirmation before a new thread is created. More flies with honey, as they say.