We will be in Venice 2 days,
it depends on how strong your legs are, but you can definitely walk to the city and walk all over it. I have walked from a ship (HAL Westerdam, actually) all the way to St Mark's SQ and back within a few hours.
Most likely you will be docking, and you will be at the largest city on the island. I don't know about walking, but a short taxi ride will get you to the city center.
as I recall, you need to take a shuttle bus to the main town, the ship will dock a distance away, but once there the city itself is small enopugh to explore on foot.
- Don't know
You will tender. Once onshore you should take the cable car to Fira, the town atop the hill (not cheap, I think 5 euros pp each way?) but once up there you can explore by foot. Look for the museum of Santorini to see original mosaics from the Akotiri civilization.
- don't know
you should dock, but I am not sure what is close to the ship. Best bet is to take a shore excursion to Pompeii
- you will dock. You can get a taxi to the train station to get to Florencee and Pisa. Start early.
you will dock, but city center is a LONG walk - take the cruise line shuttle or a taxi. A city tour is recommended to see the best stuff. If you are good at reading foreign subway maps you can see the sites on your own. See anything by Gaudi, especially the chapel Sagrada Familia
Did you go to the Sistine Chapel, if so was it hard to get to and was it crowded?
That is near Rome - Vatican City. yes, it is crowded, and it will take a long to get to from your ports.
We just don't know what we want to do but the excursions that our TA gave us are all private and really expensive.
Thanks for your help!