I dont know what italys laws are for street erformances but in the USA most cities require a performers permit to work the streets.
Much like here, it sort of depends.
1. If you're going to cause a scene, chances are police will break it up. If you're just walking about and having fun, you shouldn't draw too much attention.
2. If you're busking for cash, you may or may not need a license (I'm not sure). But there are buskers around (mostly people who dress up as characters from "carnevale", not really any performers), and I'm not sure if a) it's ok, b) you need to be licensed, or c) you need to *ahem* get friendly *ahem* with the local law enforcement. All of which are seriously potential possibilities.
3. Location - If you're in a high traffic location (major city) there will likely be a few issues. Primarily other buskers and gypsies. Buskers sort of "have their territory". Again, I'm not sure if it's licensed or a "rules of the street" thing, but everyone had their spot. Don't intrude/get to close. As for gypsies, be on the lookout - they'll pickpocket you or your specs, and I could see cops shutting you down because you make specs easy marks or because they think you ARE a gypsy.
Learn Italian
Not necessary. I did some walkups all over europe last summer and as long as you know some basic words, the cards (even in Italy where they commonly use Modiano's Napolitane 40-Card deck) are enough of a universal symbol/communication tool if you do the right tricks. Nice thing too is they don't heckle either. I didn't even really notice this until I heard Teller started performing silent because he found less people would throw beer on him at frat parties when he did.
