[Samba] Samba4 DNS - setting up forwarding zones (or how to configure clients)?

[Thomas Harold]

Let's assume that we have a network with:

domain = "addomain.example.com"

.1 - firewall server that runs BIND9, is not in the domain, but can 
resolve all DNS queries.  It is setup to forward any queries for the 
"addomain.example.com" to the internal Samba4 server.

.8 - Samba4 server (sernet packages on CentOS 6) running with integrated 
DNS in Active Directory mode.

Questions:

#1 - Where would you put the DHCPD service to hand out DHCP addresses 
(currently, our Windows 2003 domain controller handles this and 
registers the host names of clients in the "addomain.example.com" 
automatically).  I would like to put the DHCPD service on the .1 
firewall and have it send updates to the Samba4 server on .8.

#1a - Should we instead move to a setup where we create a second 
internal domain ("dhcp.example.com") for our DHCP clients?

#2 - Can Samba4 DNS be setup to forward all queries that are not for 
"addomain.example.com" to the firewall BIND DNS server?  Or should we 
continue to point our DHCP clients at the firewall as their primary DNS 
server?