changing primary domain after staging

[unclecameron]

I'm testing zcs on staging server with its own mail.tesdomain.com hostname and mx record for the install. If I move it into production I will want to change the hostname to mail.myrealhostname.com after I migrate my domains/accounts:

1. How do I change the primary installed hostname, just /etc/hostname, /etc/hosts and /etc/mailname, or would this be handled by some zimbra script?
2. Do I really need to do this? I have a legitimate reverse dns for the staging server of mail.myrealhostname.com so it should be ready to go.
3. Will this cause other problems I haven't thought of yet?