Indeed… IPv6 needs to be actively disabled, not enabled, by default.

Can’t you hide bot accounts from your settings?

Unless your ISP provides IPv6 connectivity, which gives every endpoint a globally-routable address. Firewalling at the router only works because of NAT.

You might be interested in CyclOSM to plan your routes

I can’t change my router’s DNS

Do you mean you can’t change the DNS server in the DHCP settings or the server the router itself uses? In the first case you might be able to use Pi-Hole’s DHCP server instead, while for the latter it shouldn’t be an issue - I actually usually leave upstream servers configured there to avoid loops. BTW, you might also be able to flash OpenWRT to your router

A computer that is used by a user, aka “not a server”

Probably not worth trying to actually use today. I’d leave it as it is, imo it’s better as a small piece of history - Android on PC is pretty niche