I am looking around for a control panel that can.

Create a domain, add users, add mysql databases and basically lighten the load when adding websites to my Rackspace VPS.

Zpanel does all of the above but...

I notice that it runs apache and mod_php as the apache user

What this means (I believe) is that if I have a malicious script and I have multiple users on the server then the httpd server and mod_php has full write permissions to other users webroots

So each shared account has no process and file permission separation.

So my response to that is to destroy the VPS and start again. So I'm going to keep searching for a open source control panel. Any suggestions?