7月希腊15天行程，请指教

Family 4 kid 12+15 years old, would like to see beaches, historic sites, enjoy local culture and food mid of July in Greece, flight tickets have been booked. No specific budget, middle class, reasonable approach

Q1: do we need to book ferry ticket early? (buy on spot will give trip more flexible)
Q2: plan to live in the each downtown, Airbnb v.s hotel, which is better? or both good? do we need to book ASAP to get better deal?
Q3: plan the following itinerary, any suggestions and recommendation must to see?

Day 0 arrive Athens fly to Heraklio [town] (1st) July mid
Day 1 Heraklio [beach] (2nd) 
Day 2 Heraklio [culture] (3rd) 
Day 3 Heraklio > Santoroini [Oia] (4th) 
Day 4 Santoroini [Amoudi Bay cliff/boat jump Oia] (5th)  
Day 5 Santoroini [Fira] (6th)
Day 6 Santoroini > Naxos (7th) 
Day 7 Naxos > Paros  (8th)
Day 8 Paros > Mykonos  (9th)
Day 9 Mykonos [beach] (10th) 
Day 10 Mykonos > Athens (11th)
Day 11 Athens [Acropolis] (12th)
Day 12 Athens [Temple of Olympain Zeus] (13th) 
Day 13 Athens [Parthenonas] (14th)
Day 14 Athens > flight back to Montreal (15th)