Dont know, what the problem with the GAL is.
open the address book. on my addressbook you find an entry "lookup". click this, then enter the first name of someone in the GAL.
For public folders of type address book, the besadmin-account needs "owner" permissions for any public folder. KB19111-How to configure public contact folder synchronization for BlackBerry Enterprise Server 5.0
to publish a public folder, also see this article.