Faults using mod_rewrite
The thing that leaps out at me is that the normal way to avoid redirecting valid files to the pageLoader.php handler is to use RewriteCond like so:  

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . PlugCMS/public/pageLoader.php [L]


Doing it this way means that you can easily add a new file to the site without having to add to the RewriteRule to avoid it matching.  

You usually shouldn't have to use the slug hack to get the original URL.  See here for more discussion.  

You may want to set a RewriteBase for this.  Perhaps 

RewriteBase /PlugCMS/


Which would make your rewrite rules a little shorter.  See here for more discussion.