Editing the [IMG] BBC possible?

[MoB Dudditz MD]

Is there any way to admin control or manage posted image urls remotely hosted?
I am fairly new to vBulletin so please forgive any lack of knowledge.
Users of our forum often post urls of large images via the [IMG] button in the editor
which severely affects the width of all Styles in the forum blowing them out of proportion.
These images are often large wallpapers and renders.
I like the thumb BBC which displays a 300 pixel wide thumbnail with a url of the actual image,
and since most of the users provide urls rather than attachments, I was wondering about
how to somehow implement that to the entire forums [IMG] tag use.
HTML is only allowed to administrators which does not affect any vBadvanced news articles
unless they use the [IMG] but I dont know the risks of html allowance to admins.
The following is what I have done at a test forum to get this to work
but I do not know the security nor any adverse effects of the change
even though I do not see any on the front end.

What the following does...
Makes every use of the [IMG] show thumbnail with popup to original image when clicked.
Edited the class_bbcode.php file located in the includes folder
On line 1887 of the [IMG] BBC return

PHP Code:

return '<img src="' .  $link . '" border="0" alt="" />'; 


I replaced with the following code:

PHP Code:

return '<table cellspacing="0" cellpadding="0" align="center" style="background-color:#000000; border:1px #000000 solid; color:#ffffff; font-size:11px;">
  <tr>
    <td align="center"><a href="' .  $link . '" target="_new"><img src="' .  $link . '" border="0" alt="Thumbnail" title="Thumbnail" width="300" /></a><br />Click to view the original image</td>
  </tr>
</table>'; 


It seems to work very well affecting every areas usage of the [IMG] BBC
but like I mentioned ealier, I am new to this and unaware of any easier or other way to accomplish this idea.

Does anyone know if this is going to adversely affect anything within vBulletin?
Thanks for any help.