Hi phibao,
On our free hosting we have two themes to choose from - our custom "x10Hosting Basic" control panel, which provides a simplified view for new users or people who have never used cPanel, and the standard "cPanel x3" theme that every cPanel installation has. You can switch between these two themes using the button in the top right corner. We do not provide any additional themes at this time other than these two.
The native "Backup" feature of cPanel has never been available on our services, other than a few days after the migrations when we were still configuring a few things. We purposefully disable it on each cPanel, as it creates a huge amount of server load and can cause other issues on the server. We encourage users to take their own backups by downloading their files, using a service such as FTP, and backing up their databases, using the native feature in the phpMyAdmin interface.
For both error pages and password-protect directories, I have now enabled them in each free hosting server's cPanel.
Are there any other features that you are missing?
Thank you