Hi,
As far as I can see, if you login remotely over the internet with any account other than "admin" account, the administration part is not visible, just the applications. But I guess you mean to completely disallowing logging over internet using the "admin" account, for which i didn't find any option...
Another missing features (for me) is "disallowing" http access and requiring https/ssl encrypted access only (similar to FTP Server "Allow SSL/TLS connection only") and being able to give permission/hide "add-ons" to users/groups, instead allowing everyone to see/access them.