Lodging Question

Well you could... but you'd spend a lot of time on trains and not much time seeing the places you want to see. They are all just too far apart. Besides, staying in Rome and Venice is a truly cultural experience! Of your list I consider Rome and Venice a "must." I am not a big Florence fan. Could you see your way to 5 days in Venice, stop in Florence on your way to Rome for a few hours, then spend 7 days in Rome? You can daytrip to Pompeii & Orvieto from Rome, daytrip to Padova and Verona from Venice for a change of scene. Then you'd only have to pack and unpack twice. There's plenty to do and see in-and-around Venice and Rome to fill 12 days. Just a thought if you want to cut down on the moving about.

As Laurel said, you will spend more time on & off trains if you stay in one central place. I don't suggest staying in only one place. Luckily you have at least three days in each place so you won't be moving around every day or two. Your itinerary looks good. Pack light so you can move around easily but stay in each place so you get the full experience.

You will want a place in each destination.

Just put pins on a map and you will answer your questions. You could park between Florence and Rome but you are still spending a lot of time on a train. For us that would never work because of our pattern. We like to hit the city and attractions early in morning when it is cooler and less crowd. By mid afternoon often back at the hotel for a couple of hours and hit the city that evening. Europeans in those cities tend to eat later with a lot of activity between 8 and midnight which would nice by commuting into Rome. What is so bad about unpack three times?

Can you do it? Yes. Should you do it? No freakin' way. Trust us. You would end up wasting the equivalent of a couple of your precious days on the train. It would be a little like wanting to visit Boston, Manhattan and DC all from a common location. Happy travels.