Whitelist your local network using the CLI as such -

nordvpn whitelist add subnet 192.168.0.0/16

Replace the IP with your subnet.

Cloudflare tunnels will proxy your connection so I don’t think you can do both tunnels and NordVPN together.

Perhaps a cache bypass would help with the performance issue. More details here.

The only easy way is to have customers transfer payment directly to your bank account. Other than that, dealing with credit cards, frauds, audits, chargebacks, etc… will be more than anyone can do as a “side project”.