Hi @iraqiboy90, many thanks for the pointer - the Navigation > CWP Settings > Edit Settings page was the place I needed to be - not sure how I missed it as it's at the very top of the list after Dashboard!
It wasn't entirely straightforward to correct the vhost configurations. The "NAT Local IP" setting was already showing 192.168.1.202 (I guess it picked it up from the "ifconfig" info for the active ethernet port) so rebuilding the web server configs still had no effect. In the end I unticked "Activate NAT-ed network configuration", rebuilt the config files (so they now had my external public IP address), then re-ticked the box and rebuilt the configs again. This time they had the correct IP address - 192.168.1.202. Many thanks!!
To answer you're question about using Port Forwarding instead of DMZ, the latter is essentially a NAT rule that redirects ALL incoming requests arriving at the public interface of your broadband router (other than the ones explicitly Port-Forwarded) to a nominated server on your LAN, so really it's a massive catch-all Port-Forward rule. It's dangerous to redirect all external requests to a server because that leaves it wide open to attack from outside, protected only by its own internal firewalls rules, which might be buggy or not present at all. It's much safer to forward just the requests you're expecting the server to receive as there's less scope for surprises. Furthermore, selective redirection means you can redirect other traffic to other servers on your LAN - for example, you could have separate machines running email, video conferencing, etc. The DMZ setting is only really safe to use when you point it at a dedicated firewall/router, which it how my own LAN is set up.
As for setting the server to auto-DHCP its address from the router, this is a very bad idea. It means your server could be allocated a new IP address at the whim of the router, moving it away from the DMZ or Port-Forward address configured in your router and totally breaking your CWP's ability to receive incoming requests. No, you must fix the local address in the server configuration and use that fixed address in your router's Port-Forward settings (and not the DMZ settings because that's unsafe).