Very good write up overall. I’ll start by admitting that I didn’t read all of it. But from the parts that I did read, I have some small comments. I think that Debian Stable is a great beginner distro, since it’s essentially unbreakable. With something like KDE Plasma as a DE, it’s perfect for noobs. EndeavourOS is another great one. Maybe not for beginners, but for semi-advanced usecases.
Also, I’m not sure about suggesting the Atomic family of dostros to newcomers. It might be my relative unfamiliarity with them, but I don’t think immutable distro are a good place to start. They’re definitely great to try when you’re familiar with Linux, but they’re still kind of fringe. It’s hard to get support using those.