Just returned from Italy with General Travel tips part I

We just returned from 2 weeks in Italy and here are tips we found out and hopefully will be helpful to others. These are our experiences and not necessarily shared by all who travel there. We spent 2 weeks traveling on our own Oct 5-19. We purposely planned our hotels close to the Venice Vaporetto stops and city train terminals so we wouldn't be toting our luggage big distances. Highly recommend if you are traveling by train. (see my tips for individual cities of Venice, Florence, Rome, Naples/Pompei). The below is from a perspective of someone who hasn't done a lot of subway travel (like NYC). It was relatively easy, safe and efficient, though we did walk a LOT, but then you see things you would not see in a car, bus or train.
TRAINS: Most of the time, on time. Highly recommend the EV (fast) trains from city to city: they are fast. We went second class, NO need for 1st class. There are more 2nd class coaches than first class.
I bought our tickets from Venice-Florence: Florence to Naples; Naples to Rome on the internet before we left. To get tickets and very good service (YES, using a credit card), go to <italiarail.com>. You do not have to validate these tickets--just hop on the right train. They are mailed right to you. You have reserved seats on EV and IC trains. Make sure you're in the right coach. The side of each coach will list what class, what coach number and then numbered seats inside.
We traveled with carry on (21") size luggage for 2 weeks. Very do-able, even with room for small souvenirs (though packed tight). You do have to lift your luggage above on the trains unless using storage at end of cars (not recommended unless you're sitting right there and watching it all the time). Get on the train as quickly as you can as luggage bins fill up quickly.