Today, yes. All Romans speak Italian today, its their national language. In ancient times the Romans spoke Latin, and modern Italian is, like all the other Romance languages, an offshoot of Latin.
No, because it would then be Italian. But Sicilian is considered a distinct language close to standard Italian. Neapolitan is intermediate between them.
No but they are very similar. Most European languages are similar in some ways.Here is an example of Spanish being like Italian8 in Spanish is ocho8 in Italian is otto.Also Spanish is like...