remove the damn notices for non-admin.

gistfile1.txt

// remove admin notices except admin
add_action('admin_head', function() {
    if(!current_user_can('manage_options')){
        remove_action( 'admin_notices', 'update_nag',      3  );
        remove_action( 'admin_notices', 'maintenance_nag', 5 );
        echo "<style>.notice, .update-nag , .error, .updated{ display:none!important; }</style>";
    }
});

@todo: find all actions and remove them and if it's not enough, CSS will do the trick!