Hello,
My name is Igor Seletskiy, and I am CEO at CloudLinux. I want to respond to few issues raised here. I am sorry -- I don't speak Indonesian -- so, I would have to write in English:
1) Support for cPanel -- we have plugins that work with cPanel. You don't have to control / do anything via command line
http://www.cloudlinux.com/docs/whmplugin.php
http://www.cloudlinux.com/docs/cpanel-enduser-plugin.php
2) Limits for system users: We limit cron jobs as well. If user have shell access, you can use lve_wrappers and set his shell to lve_bash or something similar (
http://www.cloudlinux.com/docs/lve_wrapper.php) -- and that will limit anything he does via shell
3) Majority (~90%) of our customers converted their production servers to CloudLinux. Beyond installation of new kernel/reboot -- we do very little to the system -- and this has been executed on hundreds of servers already. Overall -- it is very easy, and quick process. And if for some weird reason new kernel doesn't boo, or you don't like what you get -- just boot back to CentOS kernel.
If you have any other questions -- I would be happy to answer.