go in the admin cp, and change the image path for the template.. for instance, if its forums/images change it to /forums/images
or /full/path/to/forums/images
the above should work since that is how i have it setup on my site.. just add a forward slash / to the path.
as for the links, its not really that much to edit.. all you have to edit is the template header for the links, just add a / to the links. It only takes 2 minutes
if you are integrating your forums with the rest of the site it takes a few minutes, you can't expect to hit one button and have it integrated, its well worth the couple seconds it takes.