So to answer my own question... It is possible to list another IMAP user's folders, admin right don't really figure in. There must however be parent child relationship established between the two accounts, via
zmprov ma
parent@mail.com _zimbraChildAccount {zimbraIDSecondary}
After this is set one can login to IMAP (i.e. telnet or openssl) and do the following..
1 login
parent@mail.com password
1 list "/mail/child_account" "*"
and you will see all the folders in the child account.