1, It’s a good idea to give them Linux if they agreed to it and have a general understanding of what is different.

2, I installed Debian on my 81 years old friend’s shitty old laptop (it was out of curiousity), he never called me back to fix his OS. For your friend though, I’d recommend Linux Mint Debian Edition, as it feels faster than regular Mint.

I solve sudokus while commuting to work. It’s a great feeling after 100 puzzles when you can solve a hard one you couldn’t for a long time.