While the operating, owning and renting laws in Italy are pretty straight forward, explaining them isn't a one paragraph task. The first difficulty is due to American misconceptions about the "EU" as well as motor vehicle law in the US, which is the equivalent of 50 different countries bound by the equivalent of a treaty.
The are no "EU laws" pertaining to owning and operating a motor vehicle nor "EU licenses" as such. There are national laws of the member states, and there are reciprocity provisions under the treaty that is the EU. Thus the distinction between "EU" member state issued licenses non-EU member state issued licenses, which is similar to situation in the US, where there is no "US driver license", but rather licenses issued by the various states in the US.
Operating a motor vehicle: Pretty much throughout the world,
operating a motor vehicle is a privilege. The national (state in the US) laws normally pertain to operating a motor vehicle, w
ithout regard to who owns the vehicle. These laws are supplemented by international treaties.
As in the US, one must be a bona fide
resident of the issuing jurisdiction to be issued a driver license. That "residency" is based upon the issuing jurisdiction's laws. Most US states are fairly diligent about requiring proof of residency, as is Italy. And, most states share driver license data to prevent someone from holding licenses in more than one state at the same time. Obviously, it is harder to gin up proof of legal residency in a country where you are not a citizen, as home ownership or a rental address is not residency. We are US citizens who are legal residents, by resident permit, of Greece. Our resident permit (in our passports) was required to register our motor vehicles and obtain Greek driver licenses. The permits were issued well after we owned a home, and home ownership was not sufficient to declare legal residency.
Non-EU driver license holders from a nation that is a signatory to the Vienna Convention of 1968 (the treaty creating the International Driving Permit) may drive in Italy as provided by that treaty and Italian law, in which case an International Driving Permit is "required" in Italy. Non-EU license holders from non-IDP treaty states are dealt with on a case by case basis.
Yes, a simple driver license is sufficient for a non-resident to operate up to 125cc motorcycle in Italy. Has nothing to do with citizenship, but the nation issuing the driver license.
Yes, an unlimited US motorcycle endorsement (however it was issued) is recognized in Italy. If your issuing state clearly places a 125cc limit on your motorcycle endorsement, than the Italian 125cc limit would apply. I don't think any US state has such a scheme. Your US issued IDP specifically would state your motorcycle endorsement is either A1 (125cc/11 kw max) or B1 (unrestricted). Those are the only two categories recognized under the IDP treaty.
The Vienna Convention of 1968 is a treaty. Under that treaty, the signatories agree to certain provisions. Italy reserves the right, by that treaty, to require certain proof that your driver license is valid. For a license issued in a non-EU state that is a signatory to the Convention, the IDP is that proof. For an EU nation issued license, the treaty provisions of the EU prevail.
The IDP serves as a standardized translation and depiction of what you are licensed to operate. And, by that same international treaty, the authorities must accept your home license AND the IDP as sufficient and immediate proof of your license status and endorsements.
Under the treaty, the police, rental agents and insurance companies have the right to ask for an IDP. Lacking an IDP, if there is any issue concerning your home driver license, the police
and/or liability insurance issuer can hassle you
pending verification from your consulate that your license is OK - as in confiscate and hold your passport. If you run over the mayor's chicken in a small village, your IDP is your proof positive, in the local language, that you are properly licensed to operate the vehicle, and thus the rental agency's third party insurance is valid. If you don't have an IDP, the rental agency couldn't care less, as until you prove your license is valid, you, and not the agency's insurance, is liable of the damages you inflict to the third party, and without your passport, you ain't going anywhere. Thus, just because someone rents a vehicle without having to present an IDP, that does not in any way validate the notion that an IDP is not
required. Drive without an IDP at your own peril, as the only one taking the risk is YOU!
I say "can" hassle you, as Italy does subscribe to the Treaty provisions of waiver of requiring an IDP for "short-term" driving, but the waiver is at the discretion of the local police and not absolute. Operating a motor vehicle is, again, a privilege, and subject to restrictions.
Owning a motor vehicle: As in most countries, "ownership" of a motor vehicle means nothing unless it is titled and registered, and simple physical "ownership" does not convey the right to title and register a motor vehicle. Italy, as in most US states and other countries, will not title or register a motor vehicle to a non-resident. (Temporary plates for the purpose of driving to another jurisdiction is a whole separate ball of wax) However, the EU treaty grants EU citizens (and in certain cases legal residents) a bit more latitude in this definition of "residency" arena than non-EU citizens (legal residents). Keep in mind that "residency" is more complicated across national borders than across state lines in the US. Thus, while anyone can "buy" a motor vehicle in Italy, that purchase has no legal standing for title and registration unless you are a legal resident. A dealer would be reluctant to "sell" you a vehicle simply because he cannot relinquish title to you, and thus retains owner liability for the vehicle - AND knows it. A private party may be willing to assume such risk, or simply take it unknowingly. No different in the US, where private parties have "sold" vehicles and failed to register the transfer of title with the state and later find they are liable for some hair brained stunt by the purchaser.
Scooter rental in Italy - People read about all the folks who have rented scooters in Italy or see pictures of rental Vespas all lined up in a row, and come to the conclusion that there is a rental shop on every corner. After all, Italy is the Land of Vespa and Vespa Holidays.
As soon as you get away from Rome, rental shops become fewer, farther between and much smaller in inventory. Additionally, under Italian law, you cannot get "comprehensive/collision" insurance for a motor vehicle that doesn't involve a healthy deductible. For two wheel vehicles, be prepared to pay a
minimum of the first 1,000 Euro in damages to the scooter. Holding the person renting 100% liable for fire and/or theft loss is not uncommon. Thus, the 1,000 Euro or higher "hold" on your credit card. We have searched the world high and low, with professional assistance, for supplemental insurance for the Bella Italia Rallies, and believe me, it is not available. The CDW Waiver protection from your US "Diamond Encrusted Platinum Credit Card" has small print that specifically excludes PTWs and mini vans. Further, it is reimbursable coverage under a non-Italian contract, so if you use it for car damages, you will still have to pay for the damages up front and wait for reimbursement. Car rental services (firms that act as third party booking agents) that advertise "full coverage" are the same, the contract is outside Italy, and you still pay up front and wait to get your money back. Italian law precludes assignment of benefits by foreign insurers to an Italian vehicle owner.
The good news in insurance is that vehicle owners (rental agency and private) are required to have pretty robust "Third Party Insurance", which means that if you crash into a parked Lamborghini, you should have most of the damage you cause paid by the insurer.
Sorry to be so long winded, but I figured it's worth the detail if you are really interested in operating, renting or attempting to buy a scooter in Italy. It's really simple, and all you have to remember is:
1. Have an IDP or EU member state driver license and conform to the endorsements on it, and you can legally drive any properly registered vehicle identified by the IDP/license, be it a rental or a private party's (with permission, or course).
2. Do not expect to be able, in your name, to purchase, and put on the road, any motor vehicle, unless you are a legal resident of Italy.
All of the long winded crap above just explains "why".
Lastly, I am not a lawyer, and the above is not legal advice, but simply the experience of a layman.