And now that I see all the categories open at once, I see you've fallen into the same forum sin so many others do: too many sections. You've got some forums with hundreds of threads, and others with less than 10 and some even with 0. Those that are lacking content can either be sub-forums of your more active sections or just move those topics you do have there into the more active forums. A mix of both solutions will probably be necessary.
I shouldn't be infinitely scrolling down your index. Define your niche and focus on that, rather than trying to offer a section for every possible thing related to it. What is your community most interested in? (This is easily answered by looking at your most popular, active sections.) What are you interested in? Those two things will aid you greatly in defining your niche.