Ferry from Sorrento to Naples

[leg]

We are a group of 11 docking in Naples on Sunday, Nov 4. We are thinking of booking a tour of Amalfi coast to include Ravello, Positano and Sorrento and maybe stop to see the Emerald Grotto than catch the ferry back from Sorrento to Naples.

a) To save time would it be better to miss Almafi village since some of us have been there before

b) Would it be worth the 5 Euro to stop to see the Emeral Grotto

c) Since our tour will be in Nov and on a Sunday will the shops be open

d) Our tour guide has said the driver will stay with us until we purchase our tickets by ferry back to Naples-Would we be taking a chance to take the ferry instead of having our driver take us back by van-I really would not want to miss the ship as it leaves port at 6:30 and would feel better getting back earlier than later.

c) Is the ferry ride a rough trip on the water or is it a hydrofoil?

Any suggestions would be very helpful.

Thanks -