ASFS / ADFS Proxy DNS

Hi,

I am planning an ADFS environment.

I have a question about DNS.

My understanding is that I need:

1. Public DNS Record e.g. ADFS.contoso.com -> 178.2.2.2 (Public IP)
2. Firewall NATs 178.2.2.2 to 192.168.2.2 (ADFS Proxy IP)
3. Perimeter DNS Record e.g. ADFS.contoso.com -> 10.10.2.2 (ADFS IP)
4. Internal DNS Record e.g. ADFS.contoso.com -> 10.10.2.2 (ADFS IP)

My ADFS server is called SRVADFS

My questions are:

1. In the absence of not currently having a Perimeter DNS server can I simply install DNS services on the ADFS Proxy server itself, or easier - can I simply use a host file?
2. In Step 4, is this necessary simply because the server doesn't match the ADFS record name?
3. Have I missed anything?