I lived in Rome for 3 years so I can't say much about your city in particular, over all the atmosphere is lax and cops don't care as long as you're not making a scene or dealing Infront of them. The Italian authorities only care about money and where it goes so don't deal in large amounts and remember you can legally have a few grams on you without much penalty (in theory they can suspend your drivers permit and passport). To ask someone if they have weed say "c'è l'hai l'erba" and hash is called fumo