Your ISP can see what websites you visit. But even if you change DNS server it can still see that if you don’t use either a VPN or DoH/DoT.
So it’s a good idea to use DoH or DoT. It’s an improvement but it’s far from perfect because the DNS server you’ll pick will see what site you visit, you have to trust them. And your ISP still has other ways to see which site you visit.
Depends on what you need a VPN for.
I don’t know them but they seems to be from Estonia marketing themselves for evading censorship. Are you in a country that censor VPN? If not why do you think the tradeoff might be worth? The 2 hops should have an impact on bandwidth and latency and there is probably no port forwarding.
Using a VPN is just moving your trust from your ISP to the VPN. Why would you trust a VPN you know nothing about giving them access to all your internet traffic?
You’ll need to read the documentation to understand its concepts first. You don’t use mkfs but zpool to create a pool then use zfs to create the fs on it. ZFS is usually used with some sort of raid configuration so most doc will show this but you can create a pool with no replication using a single drive.
For ZFS check the instruction for your distribution here: https://openzfs.github.io/openzfs-docs/Getting Started/index.html
Yes, that’s why I ended with:
Even with secure DNS they can still see the domain name with the SNI, which is probably more reliable than an IP address. Last I checked very few websites used ECH. I would still argue that it’s better to have encrypted DNS requests than non-encrypted ones.