DNS hostname configuration suggestion?

Hi folks.
I have a situation that I’m trying to troubleshoot here.
The name of my system is as an FQDN (meaning for email, etc):
The names of my two ns servers are ns1 and ns2.keithnet.us.
My registrar will not permit me to register anything that does not follow ns1.domain, etc.
So registering serverbox.keithnet.us as an ns servern ame is not a possibility.
My server uses two public IPs as well.
To find out what the IPS of my ns1 and ns2 servers are, feel free to use a query tool on those such as NSLookup.
Now, for the question:
What I would like to do, is have ns1 and ns2.keithnet.us respectively, be automatically used for additional domains that are added to the system sot hat I don’t have to go entering the public IPs for those servers every time I add a domain.
What I was thinking of doing was changing under system settings:server templates:default settings:DNS settings (or whatever that path is) under the hsotname I thought of changign serverbox.keithnet.us to: ns1.keithnet.us
Under additonal recommended servers or whatever that box is, I thought of sticking ns2.keithnet.us.
My question is, wouldn’t changign serverbox.keithnet.us in the DNS section however for default server templates, break every other single server like mail, etc, that is already refering to my entire boxes qualified domain as serverbox.keithnet.us?
Just curious.
I hope my situation has been described in detail.
If it was not, please ask.