Yes, I'm struggling with the page width issues.
This newest version of the UBB forums is supposed to be responsive to make it work on mobile devices, but that really isn't possible with this old code because the whole thing is still using a table based structure instead of modern web standards for responsive sites.
I'll keep tweaking it but it's probably about as good as it's going to get, it does work better on phones and tablets than it used to but on wide desktop screens there are some odd issues.
I'll see what I can do about the bottom links, there is a link in the bottom menu with the blue background that takes you to the overall forum index. But do you mean back to the topic list for the forum you are on?