Alrigght here is the rough itinerary, need help refining it.

June 1st depart JFK for athens.
——-Greece
-2 days athens
-2 days santorini
-2 days crete
(ferry from crete to italy, or if thee is none, ferry to bari then to italy)
——Italy
-3 days rome
-2 days florence
-3 cinque terre
-2 venice
——-Ausria
-3 days in viena
——-Switzerland
-3 days grimelwald
——-France
-not sure exactly where to go

so, what do you guys recommend, I fly home on the 5th of july. so june 1st to july 5th. What should i cut/add?