It is possible if you use pivpn (or any other VPN software) and double hop it to your pivpn provider.

Device -> pivpn (uses pihole) -> mullvad -> internet

I just get the wireguard configs from mullvad and edit them to properly work. Also works to get around device limits of the VPN.

I use Quad9 for my upstream.

I would stay on both. Keep reddit just for the more specific subreddits I like that aren't big here.

I use opensuse with kde and I love it. Have been using it for 2 years now.

For server use at home I use Ubuntu Server and Alma Linux (mostly)

At work it is all RedHat.