I like this idea, but I think you should work a bit of history/philosophy into each lesson by explaining why things work the way they do. The students are unlikely to engage with a history of a system they've never used before, so starting with that will lose their attention before you've even gotten it. Giving them a bit at a time means that they will slowly build a mental model of how *nix works and is built.

Hot tip: if your skylight gets smashed in by hail or branches during a storm, you can use an umbrella like this to keep most of the rain out until you can get it repaired.

OSM for day hikes and Avenza for anything more serious.

Yes, but you have to buy a subscription to Protonmail Bridge which see decrypts the emails for Thunderbird.