I`m using the Plugin Membership - I want certain levels to have access to all content on the site -

I want paying members - to see the whole site - how can I grant them access to the whole site - when I tick the access levels - the system says: only the most recent 50 pages are shown - how can i grant access to the pages I cant see -and why cant I just grant access to the top level page - so that access is automatically granted to the sublevel pages?