There are two types of changes that can be made to the forum.
1. Template & Skin Changes
Changes that can be made to the forum simply by us editing templates. This is mainly to do with stuff putting things in different places on the page, etc.
2. Feature Changes
Pretty much anything else.
Please be aware, if you want to do something which falls under #2, you're going to need to show us how it can be done. Most of the time, this will be through the use of a vB modification at vbulletin.org. You can find these here.
If you can't find a mod at vbulletin.org that will do it, then you'll either have to look elsewhere for something which will, or actually have the ability to code it for us (or know someone who can). Because otherwise, we just don't have the ability to code this kind of thing up from scratch ourselves.