Yeah, NAT is fairly secure in the sense that it blocks incoming connections... you're kind of a security nut if you lock down all ports. Anyone outgoing will just stream over 80 or 443 anyways, port based firewalls are pretty antiquated. You can't really lock down port 80 and still have a functional network unless you whitelist every device you connect.
But you can lock down that egress for your cameras. Why does your camera need to establish any outbound stream at all? Might want to keep an eye on that...
