Code
 

I'm the freak, who is reviewing your code in his free-time and it's shocking.

1. You don't have any code standards. Pls define some and use them.
2. code documentations
There are many "nonsense documentations"
For example check the widget classes
PHP Code:
/**
* Test Widget Controller
*
* @package vBulletin
* @author vBulletin Development Team
* @version $Revision: 37230 $
* @since $Date: 2010-05-28 11:50:59 -0700 (Fri, 28 May 2010) $
* @copyright vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
*/

Use the right one or remove it, but this is unnecessary.

3. Deprecated Code
Pls mark deprecated functions / methods as deprecated, so i know that i don't have to report the issues with them;)
For example:
PHP Code:
// ################################################## ###########################
/**
* Builds a Javascript line to add a new attachment to the vB_Attachments object
*
* Assumes that all data is cleaned and htmlspecialchars'd
*
* @param integer Attachment ID
* @param string File name (myattachment.gif etc.)
* @param string Filesize (124 KB etc.)
* @param string Extension type (gif, jpg etc.)
* @param string (Optional) Javascript prefix, such as 'window.opener.'
*
* @return string
*/
function construct_attachment_add_js($attachmentid, $filename, $filesize, $extension, $prefix = '')
{
return $prefix . "vB_Attachments.add($attachmentid, '" . addslashes_js($filename) . "', '" . addslashes_js($filesize) . "', '$stylevar[imgdir_attach]/$extension.gif');\n";
}

from functions_editor.php
I wanted to report this because of $stylevar but as i checked the code, i couldn't find any call of this function because it was refactored to vbattach.php => http://tracker.vbulletin.com/browse/VBIV-8511