Launa has it in a nutshell....plus go to the Princess Website and look at all the excursions they offer copy and paste them then highlight all the bits you fancy and work out your own day trips for a fraction of the cost. I would suggest that you use the ships excursion to Florence just to get you there and back and do your own things there and go to Rome on the train from the port, very easy, and work out your own sight-seeing there too....Heathe.
Should be relatively easy. You are obviously computer literate to be on here. Use Google to search for local taxi's and tour operators and check out their quotations. Calculate the costs from the Cruise Companies Tours advanced booking brochure and compare them with what you have obtained on the internet. There, easy. We did it three times in the Adriatic last year. One small warning though. They may require, quite rightly, a deposit. If your cruise line visit is then cancelled or late, no tears please.
Get on the train for Rome - its really easy and cheap - it took us about 15 minutes to walk to the train station, and the journey took about 50 minutes. Beware of taxis in Italy - they are really expensive.
For 5 adults it will undoubtedly be cheaper to "do your own thing". I would suggest that you take a taxi from the dockside at Livorno to the train station which costs about 15 euros each way - very over-priced but the taxi drivers want to take you on a tour, not ferry you to the station so they make you pay for the privilege! The train fare from Livorno to Pisa costs 1 euro 70 cents each for a return ticket and the journey takes about 15 minutes. It is a 15-20 minute walk from the station to the Field of Miracles or you can catch a bus. The walk takes you through the heart of Pisa and along the main shopping street all of which is level. You can pre-book tickets online to climb the Leaning Tower which avoids the need to queue. However, you have to choose a particular time-slot which can put you under pressure of time. I found that the queues were dealt with quite efficiently.
At Civitavecchia, I would also recommend taking the train to Rome.Catch the free shuttle bus from the dockside to the dock gates. From there it is a 15 minute walk to the train station. The train fare costs 9 euros each for a return ticket and this includes use of the metro in Rome. You need to be careful which train you catch because some take much longer than others to reach Rome. The faster ones take about 50 minutes. I recommend catching as early a train as possible to make the most of your day in Rome. I would also suggest you use the ticket machine to buy your tickets as the queues at the ticket office can cause you to miss your train as I know to my cost. Be aware that the trains can be very crowded and you aren't guaranteed to get a seat. The trains can also get very hot.
It is obviously much more convenient to take the ship's tours and you have the added security of knowing that if your tour arrives back late, the ship won't have sailed without you! But for flexibility in your itinerary and the opportunity to do a tour far more cheaply than a ship's tour doing the same thing, travel independently.
Many thanks for the suggestions