@caver01 thanks again. I read a bit now and I think I understand the role of retroarch, acting as an interface between emulationstation and the various emulators.
That clears up a lot!
You are right about the shift function on my ipac too.
But I cannot end the Vice version on Retropie - even when using a keyboard. I need to open the vice menu (F12) and then navigate to "Quit vice".
But it's okay. For C64 emulation I find myself grabbing for the keyboard quite often.
Cheers,
Robin