It would be largely fine, but be careful. Being immutable, a lot of things that you would expect will work differently or not at all. I would not recommend it, but if you’re in for a challenge, it’s not bad.

Correct, but new users don’t want to need the command line for something as simple as installing packages.

That should work. One of the benefits of Wayland is that it’s better at scaling than X11. What version of KDE are you running? Is there a switch between two different types of scaling (one is blurry for XWayland applications but works for all of them, the other is sharp for all applications but only some XWayland applications and all Wayland applications work)?

Pretty much anything with XFCE, LXDE/LXQt, Cinnamon, MATE, a window manager like Sway or i3, or probably some others I’m forgetting, will work just fine. GNOME and KDE are the most popular but the slowest, and from what I remember, Deepin, Budgie, and Pantheon are somewhat slow.