This really should be in the “transport forum.” 

1.  You can rent a car in Italy and drive to Switzerland.  You just need your valid driver’s license from your home country and a credit card.  An international driving permit (proof you have a valid driver’s license that is recognized by most countries worldwide) is a good idea but usually not necessary — check the fine print at orbitz, expedia, etc.

2.  Driving in two countries adds considerable expense to a rental car as there are additional taxes and insurance and drop off charges to rent in one country and return in another are usually very high.  I would also expect to pay some tolls on this route.

3.  Based on the AAA planning map of Europe, I’d estimate the drive time at about 8 hours.