I know what you mean about the large slabs, I'm the same way.

I'll generally be able to figure out what's changed between what I have and what I'm supposed to replace it with and can hack it accordingly.
For some reason, this thing uses a customized error page and function. That's all fine and dandy, but I like everything to be as consistent as possible

so I modified the warning system to use vB's "standard error" template. It's rather simple, to do so:
Find this code in the includes/functions_warning.php:
PHP Code:
function RunError($message)
{
// Theres probably some globals below not in use, uhm, who cares?
global $vbulletin, $session, $stylevar, $_POST, $vbphrase,$navbits,$show,$header;
global $templatecache, $db, $vbulletin, $style,$headinclude,$footer;
global $tempusagecache, $templateassoc, $pmbox,$pmtext;
eval('$warn_page .= "' . fetch_template('warn_error') . '";');
$navbits = construct_navbits($navbits);
eval('$navbar = "' . fetch_template('navbar') . '";');
eval('print_output("' . fetch_template('WARN') . '");');
exit;
}
And replace it with this:
PHP Code:
function RunError($errormessage)
{
global $vbulletin, $session, $stylevar, $vbphrase, $header;
global $templatecache, $db, $style, $headinclude, $footer;
$pagetitle = 'Advanced Warning System - Error!';
eval('print_output("' . fetch_template('STANDARD_ERROR') . '");');
exit;
}
You'll notice I removed the globals that weren't needed... I basically played with each one until I found the ones that made the error pages work and the ones that didn't. You can change the text in the $pagetitle part to fit your forum or needs for the window title of the errors (these errors are used when you try to warn on a post that's already been warned assuming you have that disallowed, etc).
My advice to anyone who has a lot of modifications on their forum or a non-default skin would be... careful with the template edits

because with stuff like your postbit or memberinfo templates it's easy to mess stuff up if the code you're supposed to be replacing over isn't exactly as listed in the instructions.