Hey you! Long time no see. Good to see that you haven't forgotten us
!!
I think Madrid is actually the closest European city to Marrakech. It may be the cheapest to fly into, but no sure. Barcelona may be an option as well.
Rome can be an option then work your way to the coast, knock out Switzerland, then make your way to Marrakech.
Lastly, you can pick Zurich as your home base then take two separate cheap flights to Italy (somewhere), then to Marrakech and back to Zurich.
I guess it all depends on your budget.