Thanks for the dining advice as that is #2 on the list of things to do in Rome for my daughter & her friend Trevi#1 (21yrs old) Any advice if we want to see Sorrento on the back from Pompeii to Naples? also any thoughts about navigating Florence?

Sorrento is not on the way back. Its Naples, Pompeii then Sorrento. If you want to go to Sorrento you need to get back on the train (same side you got off at Pompeii) and travel about 20 minutes more moving southward. You could then take the boat back from Sorrento to Naples. Here is link to boat schedule. Everything you need to know:
Linea A: Capo di Sorrento - Piazza Tasso - Sant'Agnello - Piano di Sorrento - Meta
Linea B: Piazza Tasso - Marina Piccola
Linea C: Sant'Agnello - Marina Piccola
Linea D: Piazza Tasso - Marina Grande
Tickets are available from bars and news kiosks; remember to validate them in the machine on the bus.
Ferry services run from Marina Piccola, and tickets can be bought at kiosks next to the port. Destinations include Naples, Capri, Ischia and Amalfi, but services are seasonal and subject to changes. Site is hard to figure out here is phone 892.123 just call when in you get to Sorrento so you know how to use your time. Carmar is the ferry line.
SITA run blue and green buses covering a wider area. Destinations include Positano, Amalfi, Massa Lubrense, Sant'Agata. Buses depart from the Circumvesuviana Station in Sorrento, and tickets can be bought at bars and news stands. For Positano and Amalfi, buses run irregularly, approximately 40 minutes apart, although some gaps are longer, and there are fewer services on a Sunday. Journey length for Positano is 35 minutes, and for Amalfi 1hr 35mins. You can also take a boat from Amalfi back to Naples but that would be pushing it unless your boat has a late depature time.
What do you want to know about Florence?

You'll love Voyager of the Seas, did it last spring--a transatlantic. You say you booked a tour in Barcelona, but that city's not on your port of call list. You can get a bus that goes into that city and stops where you want to stop at the best things to see. I agree with those who say to do Rome on your own. We did a guided tour, then Vatican City on our own and were surprised at the hospitality and ease of getting around from there into the Basilica and Square. We'll do Navigator of the Seas out of Miami to Rome in the spring--similar ship, great price with $300 onboard credit, will fly home from Rome.