Very interesting, thanks!

Ubuntu or Mint are among the most noob-friendly.

But probably the biggest impact will be whether you go with Gnome or KDE. KDE is more Windows-like so could be a softer landing.

I’ve read a lot of stories where installing Linux resulted in less support calls, not more. It depends on how ambitious the user is - if they’re mostly just staying in their lane and browsing the web it should be rock solid.

80% of the time, compiling something from source is just a matter of downloading the code, opening a terminal and changing to the directory containing the source and running these commands:

./configure
make
make install

It’s the same 3 commands, 80% of the time.

Installing the prerequisites can be tricky, if the docs are lacking.