To delete pilots, simply go into their Profiles through your admin panel, click their name, and click the tab "Pilot Options"; on the bottom of this screen you will see the option to "Delete Pilot". This is irreversible, though.
As for the second problem - use the "remember me" function, and also make sure the links are to "http://yoursite.com" and not "http://www.yoursite.com". I find by including the "www." it logs you out of the system.
Oh, and this should be in the "Support Forum".
Hope this helps,
James