When users signup via the amember form, they get added into the wordpress subscriber role as they should. However, I deleted a member in amember admin but they still show as a member (subscriber) in the wordpress admin and can therefore still access protected content. Is this an error ? I have cleared cache and refreshed the wp-admin and the user is still in there.
Make sure you checked the "Remove Users" box as documented on this page. Also I am not sure if the deleted user is removed from WordPress immediately. It may happen when the cron job runs. When the integration is set up correctly, the user is not given a way to log into WordPress. Registration in WordPress is turned off. Settings in the aMember plugin for WordPress cause all attempts to access the WordPress login or profile page redirects to aMember. So, even if you saw a user in the WordPress user list they should not be able to login if they do not have an aMember account.