Beware of gypsys with kids, and/or pushing strollers, carrying a piece of cardboard. The kids are a distraction, and the cardboard covers their hand while they try to pick your pocket. If they approach you, yell "attentione" to draw attention to you and distract them.
Like mimi, I suspect the backpack is fine, but you have to beware of the running snatch if you're resting. It's fine on you, but when you're resting, it's a big target... with straps that are easy to grab on the run. Having said that, I carried one in Italy and had no problem.
Remember, Italy is barely a "second world" country...but it beautiful indeed.
Also, some of the cathedrals will require that women have their knees and shoulders covered. It's a good idea to cover a light weight scarf if you want to enter these sites.
I'll PM you our travel journal from our trip there a few years ago.
If you don't grow where you're planted, you'll never BLOOM - Will Rogers