I am surprised nobody has suggested this before. So I am going to post out my suggestions.
My first suggestion is the ability to post on any page. Basically, it eliminates the requirement that you have to be in the last page to post a comment in the thread. Like this picture currently depicts.
I don't understand why you are forced to go to the last page just to post a comment in a thread. All I see is it just poses a pointless impediment that shouldn't be there in the first place. Take a look at a Facepunch thread. You can make a post in any page of the thread. Much better right?
Which leads me to my second suggestion. A redirect link to the last post of a thread. Take a look at the current main forums page.
Seems normal right? It's states the last person who posted in a thread, but you can't even go immediately go to the last post. The only way you could get to that post is to click in the thread. And if the thread has multiple pages, you have to click on the last page and then scroll down just to get to that post. Let's take look at a Facepunch forum page.
Notice by clicking in the small gray circle on the right leads immediately go to the last post in that thread. Which I suggest that should be implemented in the forums, so that people can immediately get to the last post without having to go through multiple pages to just get to the post.
Which I will get to my final suggestion. The subforum page. God, it's look like a mess. The page number listing stretches up the subforum pages.
Instead of just listing every single page number, why not just do what Facepunch Forums is doing?
Just condense the page numbers to just listing only the first and last few page numbers. Looks a lot more cleaner that way and also saves space as well.
So that's my two cents about my forum improvements. The suggestions are small, but it will improve the KYM forums usability by a lot if these suggestions were to take effect.