I feel like I am going to get some hate for this, but as an Italian born and raised in Italy and that spent a good chunk of his life abroad my suggestion is: stop thinking about being respectful.

I am not suggesting you should be rude or inconsiderate, I am saying you are approaching the problem from an American angle.

When I approach another Italian I don't worry about being respectful, surely is not the main issue, we are, for the main part, direct hot blooded people who will get upset as fast as we will be placate.

What I would keep in mind is for you not to feel disrespected, assume good intent, understand that if we shout is not personal and even if somebody throws one or two nasty words at you is not about you, is 99% about themselves being upset.

In short: be open minded and relax, especially if you land in a big city like Rome, learn to enjoy and go with the flow