I've contacted a hetzner system engineer.
He said following:
I't a must have for them:
- Possibility for creating paswort protected folders in the ispconfig panel.
- WebFtp in the controlpanel
and a possibility for the customers to backup their data (Mail, Web an Database) and a possibility to restore the data
If you integrat this in the next version, they'll test it an the chance is big that they add this to their portfolio.