The first thing you must accept is that you cannot "do it all" whether on a tour or on your own. In fact, I think the biggest mistake many cruisers make is to do too much, and hence they really do nothing! (hope that makes sense). All those ports can be done on your own, if you want to take the time to do your homework, and you prioritize what is most important to see and do. As an example, you can do Pompeii, Sorrento and Capri on your own, but your time in Capri is going to be pretty short, and you are also going to have to keep Pompeii to no more than 2 hours (this assumes you get to Pompeii by around the 9 am opening). Florence and Rome plans are dictated by how much time (if any) you want to spend in museums. One problem with doing Florence on your own is getting from the ship to the Livorno train station. Athens is quite easy to do on your own by using the train/subway from Pireaus to the city. Villefranche offers many options, and you do have easy access to the train line as well as buses from this port. If you can further refine your options, both ftroute and I can give you lots of detailed help.