Yes, you can install on one machine, move the drive to a different machine, and it should mostly just work (unless they are different architectures and the packages aren’t compatible). I’ve recently moved an old Arch install into a basically new computer and after changing the microcode it just works fine.

Looks great! I recently put together a similar build with the same mobo/CPU, and it works very well. Just note that I had to do some fiddling in bios options to get it to shutdown/sleep properly, but all is good now

I doubt it - the bootloader is very different on iPads and I don’t think it would let you boot a different OS

For a launcher, I’ve been using Neo Launcher (which is on IzzyOnDroid). It’s not as feature full as Nova but it’s pretty similar in spirit and style

Yeah, my ZenFone 9 has been a great upgrade from my old Pixel 3a. I’d expect the ZenFone 10 to be slightly even better