Your going to get an error when you try & rebuild, again, since you have ClamAV & Amavis disabled and removed.
rDNS is checking incoming emails for a valid rDNS/PTR, I"ve found allot of people don't have that configured, or is misconfigured, so I leave it unchecked.
But you do want OpenDKIM to generate you signatures, and then you can copy them from the CWP server over to whomever you use for a DNS.