Regarding snapshots, I use a setup, where at the root of the btrfs partition I have the subvolumes “rootfs”, “home”, and a directory “snapshots”. I can boot into a snapshot by changing the mount options for the rootfs in the kernel command line, e.g.setting subvol=snapshots/rootfs-yyyy-mm-dd.

The only difference between a snapshot and a regular subvolume is that snapshots are readonly by default, you can keep a writable copy of a snapshot beside it for recovery purposes, if you need it. As long as nothing is written in it, it shouldn’t use any significant extra space.

I know that, but that does not give apps root access. Unless you mean something else by root access than being run with root privileges

But Shift+insert currently pastes the primary selection, not the copy-paste clipboard. So it doesn’t do the same as Ctrl+V.

Well, the article proposes to use dedicated copy and paste keys. If you don’t have an insert key, you probably don’t have those either.

And best of all, you get an OS that is secure, which traditional Linux distros aren’t due to every app having root access by default.

What? Which distro runs everything as root by default?