Most of the time the customer router is controlled by the ISP. And I don't see why you are so pedantic on this, the point is about how NAT is generally deployed, and for consumers, this is with a single IP, stateful firewall and UPnP for port forwarding. And this might change with IPv6.
No, that is how IP(v4) is commonly deployed: With a single IP, NAT, UPnP for port forwarding, and a stateful firewall.
Yes, that could change with IPv6. But it still doesn't have anything to do with NAT. Just because stateful firewalling happens on the same device as NAT, doesn't somehow make it a property of NAT. There also usually is a web interface on the same device. Now, with IPv6 that could change as well. Does that mean that web interfaces are a property of NAT? Or that it would be sensible to say "NAT is commonly deployed with a web interface"?
