Another friend of mine just reminded me, and I think I have read someone on this thread have done it, but I still want to check:
my friend can also buy a ticket such as:
CDG-PVG-MUC, or FRA-PVG-ZRH.
Both are still eligible since France and Germany are not the same country, and likewise Germany and Switzerland are not?
Correct. France, Germany, and Switzerland are 3 different countries. The fact that two of them are in the EU doesn't matter.