1) Root goes on top, and you don't get anything like "root" over your group of users. By default, all of your users are in the same group, so if you have Enhanced Security turned off for each group, you have limited visibility into all the users' directories. Then again, so do all of them.
2) I don't see a suggestion submitted when I search for "ACL" here:
The UNIX Groups can give you something similar to Root access if you make each user their own group and add your root user to each group, then make everything group read/write. Root will need to use SFTP to get around, which many FTP clients can do. In fact, it's much more secure to set your FTP clients to use SFTP. Just make sure you have SSH turned on for each user.