One easy trick is to just hide them, of course the functionality would be still accessible via the URL by appending the respective ?do= action. To hide them, edit the main.php of the template search for "button" and change the two button calls to:
<?php if(auth_quickaclcheck($ID) == AUTH_ADMIN) tpl_button('revisions') ?>
<?php if(auth_quickaclcheck($ID) == AUTH_ADMIN) tpl_button('edit') ?>
If you want to really disable it you'd have to create an action plugin too which intercepts the action and checks if you're admin or not.
Hope that helps.