I've not done the 10 day tour, but took the 21BOE tour, which includes a week touring Venice, Florence, Rome and the Cinque Terre. Anything is a possibility, but if you're wanting more, have you considered taking a longer Italy tour than the 10 day one? A couple of them include the Cinque Terre. If you're new to traveling, taking a longer tour might be easier than trying to navigate on your own. The Cinque Terre is amazing and very much worth the visit! I wouldn't want to tackle the hair raising drive to get there, but you can take a train. Others more familiar can give you better advice as to extending your trip. I personally suggest extending to a longer tour.
Venice, Florence and Rome all have great things to see and do! I loved Venice the best. It was great to explore on foot, and as a single woman traveler I felt very safe there, even after dark. I adored St Marks Square and could have stayed there all day and night, just sipping limoncello and people watching! It can be disappointingly crowded in the afternoons, but that's a good time to explore the museums and shops, nap at your hotel or do something else away from the crowds. At sunrise and sunset you get dreamy, postcard Venice. Great city.
I didn't love Florence and Rome quite as much just because I'm a small town girl and found the big cities a bit intimidating. That being said, I did find many things to enjoy. There is so much art and history to explore there! Seeing the David statue in Florence... surreal. I also did a LOT of great shopping in Florence with a fellow tour mate and our impeccably dressed bus driver! We all bought a LOT of scarves. My daughter was due to get married just after my return, so I bought Italian scarves for all the bridesmaids and Italian leather wallets for the groomsmen. We had a lot of fun on our shopping trip! What can you say about Rome? It's ROME! Seeing the Colosseum, the Forum and the Pantheon up close and in person is absolutely... magnificent. I'm not a foodie, at all, but the food and wine in Italy were absolutely delicious. The people were all very kind as well. I also visited Vatican City. I'm not a Catholic, but you don't have to be to appreciate the beautiful art and history there. How many people can say they saw the Sistine Chapel? I can! Italy was the country I was indifferent towards before the tour. But after... Lets just say, I'll be returning to Italy on an RS tour (also in September!) and I'm quite excited about it!
If you get the chance to visit the Cinque Terre, do so. There is nothing to hate and everything to love. If you can't relax there, you'll never relax! Whether you just pick a few feet of beach, keep a drink in your hand and never leave that, or whether you explore all of the local towns, or something in-between, it's all good. The areas are all postcard beautiful, the people charming and eager to please. It's easy to get around and explore in a variety of ways. The pesto... my mouth is watering just writing the word...
However your trip goes, Italy is fantastic and you are in for a wonderful treat! Definitely stay as long as you can. Have a great time!
Lisa