Traveling by train to different destinations while in Italy, Rome will be our general area for departure for each trip. Rome to Venice return to Rome Rome to florence, florence to sienna florence to pisa to rome Rome to Pompeii to Sorrento via Naples Sorrento to almafi coast to Rome
What are best option purchase a 6 day rail pas or pay as you go.
Go to the Trenitalia website and look up the cost of each ticket. Add it up. Compare it to the cost of a 6 day 2nd class saver railpass. You have several things going for you vs a Eurail pass. First, by getting a one country pass you can get second class pass. A three county Eurail pass is only in 1st class. Second, fares in Italy are fairly low, and so is the rail pass. A Eurail pass costs more because you might use it in more expensive countries. A six day, saver pass for two will cost you $474, €355, or €59 per day. Some trains will be more than that for P-P, but you'll have to add approx €20 for two to the railpass cost for a supplement. Some of the legs you have indicated will be a lot less P-P. You have to do the math.
Linda,
Florence to Siena is best done by bus (easier, faster). The Circumvesuviana which is not part of the Italian State railway goes from Naples to Pompeii and Sorrento. Sorrento to Amalfi coast is not done by train (buses, ferries, cars) back to Rome will be from Naples or Salerno.