The script would need to be rewritten to make posted images clickable, and it would slow the speed of the script down by over 200% surely. As for your header image, this script isn't programmed to be integrated with the vB post code (which slows forums down if you do it that way), so it will resize every single image over your set width, regardless if it's in a post or on the page. The work around to this, and the one I use at
www.forum-central.com, is to break the header up into a 2 or 3 part image and use tables to align it. That would be more webfriendly than having an 800 pixel wide image, anyway.