When I activate the plugin, the following error is displayed at the top of the admin pages:
Notice: has_cap was called with an argument that is deprecated since version 2.0! Usage of user levels by plugins and themes is deprecated. Use roles and capabilities instead. in /var/www/vhosts/exeterchiefs.co.uk/httpdocs/wp-includes/functions.php on line 2712
I can't trace it back to where it is origianating from, in your plugin, as you don't seem to make any calls to 'has_cap'.