Cant you just use an IF statement?
<!-- IF (PHP.usr.id != xxx -->
plugins page here
<!-- ELSE -->
Sorry, you cant see this page yet -->
<!-- ENDIF -->
(where xxx is his user ID)
Like this you can hide all the info from the page so he cant acces it while you and other admins can see it like normal.
IMHO there should be more options to allow users in specific admin areas. Like that you can slowly increase what a (future) admin can see and let him practise and teach things without having access to other stuff.
<img src="http://www.armaholic.com/datas/thumbs/green-sea-battalion-uniforms-version-03-preview_4.jpg" alt="green-sea-battalion-uniforms-version-03-" />
