It’s fine to use it on multiple devices at home, as long as it’s all coming from the same public IP (if you use the same internet connection for all your devices, you’re good.)
You pretty much got it, except for the fifth point.
A desktop environment (“DE”) is separate from the compositor (X11 or Wayland), but can’t exist without it.
At the end of the day, a DE is really just a “window manager” with a bunch of bundled applications, like taskbars/panels, a file manager, an app menu, etc. It’s as minimal or as feature rich as you want it to be.
The window manager dictates what to draw on the screen and where, but the compositor is what actually does the work. One is kind of useless without the other.
Hopefully that makes sense, I’m not a rocket surgeon.
Nobara is a great suggestion by @el_gringo_loco, but I’d also throw out a suggestion for Bazzite if you want the “SteamOS”/Steam Deck experience.
It does have the KDE desktop environment underneath to do all the non-gaming stuff as well, but if gaming is your number one focus, it’s a pretty cool setup.
I really like cascadia-code for my terminal (nerdfonts.com has the version with all the ligatures)
I don’t do any graphic design or anything like that, so the fonts that come with any modern distro seem to do the trick - maybe I’d install ttf-ms-fonts for better compatibility when dealing with files across multiple operating systems.