Next part is going to be security and some storage off-loading on memory (mostly avoiding logs on storage). Then probably a part 3 on server stack (nginx/apache) and network.
I never encounter this CG/NAT, I’m wondering how it goes with online game for instance (wouldn’t it be a no-go for many casual users?). I have set-up once a VPN as a reverse-proxy, buying the lowest tiers of VPS (Virtual Private Server) as it would had a public IP to use and just forward everything to the server (which was in a shared space so kind of the same as CG/NAT). This is not 100% host but at least the VPS is just a gateway and doesn’t hold anything and is easily replaceable.