Hi!!
First of all, thnaks for your nice plugin. I'm testing it and seem to work OK.
I'd like to make you a suggestion. In my new site I'm using a role managing plugin to control users privileges. Adding following few lines at the beginning of your code you can achieve assigning/removing use or MyLinksOrder to specific users:
global $wp_roles;
if ( ! isset($wp_roles) ) $wp_roles = new WP_Roles();
$wp_roles->add_cap('editor','mylinkorder');
Tested and working!!