hello

I never saw a rental contract without terms, i even don't know if they exists or if they are legal.

The legal terms in italy are 4 years + 4 years for residentaial properties and 8 years + 8 years for residential properties. That's the minum your are able to set longer terms but i think that a unlimited contract is not possible.

If you have a regoular contract you can be 100% SURE that no one will be able to kick you out.