On #3, I'll just plug Mageia again. I use the KDE version (I know, I know, you didn't want to know) since 2011, and it's the only linux I've ever used that "just works". I've had it on several laptops and a desktop, and haven't once touched a config file by hand. I've more or less forgotten all of my old Linux hand-editing juju.

They're the community-driven spinoff from Mandriva, and they're the only Linux I'd recommend to anyone anymore: https://www.mageia.org/