20 Year Anniversary - Going on a cruise (Greece / Italy)

We live in NY.

My wife and I originally wanted to go to Italy for our honeymoon. That didn’t work out so we vowed to go for our 20th.

We didn’t have intentions of taking a cruise. However, after a lot of deliberating we decided to bring our 14 & 17 year old boys and then landed on a cruise.

Norwegian - Ship departs out of Rome to visit:
Santorini
Athens
Corfu
Malta
Messina
Naples/Pompei
Florence/Pisa

I’m certain this isn’t the best way to see these two countries but I’m happy we’re going as a family.

Does anyone have any suggestions for the limited amount of time we have at each port? Tours - yes or no? Any musts? Must nots? Etc.

I love 2p2 for these types do things.

Thank you