The spruce and other local conifers (I live by the Bohemian Forest/Bayerischer Wald) have pollen that seems to be low allergenic by design. I know a lot of people who are allergic to birch or weed pollen, but not to spruce.
This thing just makes it easier to dump the firmware, but it's not a revolution or anything. The STM issues have been known about for a while, and with a bit of effort, you can dump it yourself without this or any expensive tools, as I once did: https://analogic.cz/rs41-rpm411/
Cloudflare does not have any IPv4 blocks in North Korea. Geolocation databases use RIPE as the primary source and then make estimates using various tools.
For only your personal use sure. If you run stack for more than couple users you will sooner or later hit problems not with software itself but with outer world.
Running self-hosting email is not problem. There is so much solutions to run easily own server these days. But the main problem is that you need a lot of knowledge to do that properly - software might help but it will never be "run and forget" service type.
For example large part of IT professionals which contacts our support (https://poste.io) don't get difference between SMTP envelope and from/to headers.
FLARM is very bad example especialy for DIY community. They have proprietary chips, firmware and are running non opensourced protocol. Also they are actively trying to prevent reverse engineering with cryptography and killing old/diy devices with protocol timebombs...
These tutorials are nice but you can just hack https://hub.docker.com/r/analogic/poste.io (shameless ad) or any other containerized solution. You will get fully working solution in couple minutes and it will be somewhat easy to keep mailserver updated...