Hmm, sounds interesting. Any interesting/notable differences that set this project apart from other similar projects like IPFS?

I would just create a point to point VPN connection and run it over that (for axample an IPsec tunnel using strongswan)

I disagree, it is great to use. Yes, some things are more difficult but as OP mentioned he wants to learn more, and running your own cluster for your services is an amazing way to learn k8s.

Yup, sorry to be the bearer of bad news🥲

Plenty of IPv4 only networks still exist from which you would not be able to access the services. I am in a similar situation as OP with my offsite address being IPv6 + CGNAT IPv4 and my own address being IPv4 only.

I use snapdrop/pairdrop for quick and easy file transfers, but I found transfers to be quite slow, so this may be an alternative for larger files.

If you don’t want to run a DNS server and don’t want to set up different internal & external IPs you can also use NAT Hairpinning