With AD integration, this ain't your father's DNS.
This is shared function here as we are at the server level split between
Unix and Windows in separate zones. We have done similar to what you
propose. Communication MUST be there. Each must know what the other is
doing.
I am not sure what you
You should never have an AD domain controller doing your outside DNS. Let
them have the DNS for the world and you keep it for the inside on the domain
controllers. Name your Domain different than your actual web presence (that may
be too late). This way if it doesn't find it in your DNS then