I have been "home to Italy" every year for the past 5 solo. and 2 years ago i took a sabatical in Sorrento for 3 months. Since i am older most people dont notice me but i had no problem traveling throughout the country and visiting most of the sites i wanted to see.
suggestions: some of my best hotel accomodations have been booked with monestary.com. throughout italy there are many convents/monestaries that no longer are used as school or hve enough memebers. They rent CLEAN room, are safe and in the case of the one i stayed in in Spoletto had some of the best food of my entire trip.
The sisters and staff usually think it is interesting that you are off on your own and are curious. In most of the locations i meet travelers from other countries as well as Italy. If you want more of a service/social setting the properties with Venere have been great. i travel by train so i prefer to be within walking distance of the train stations. I have not tried hotels but i understand they are getting better all the time.
suggestion: the VERY BEST trip i had was the one where i took a week of language lessions (in sorrento) i met women from 5 other countries,I was the only American in the school and started to feel like an Italian instead of a tourist.
buono viaggio www.hometoitaly.com