The beaches near Taormina are nice, but not exceptional, certainly no comparison to those on Sardinia. If you're looking to enjoy a beautiful beach, go to Sardinia or perhaps along the Tirrenian coast of southern Campania (e.g. Palinuro). If you would prefer a very beautiful medieval town with stunning views of the sea and of Mt. Etna, go to Taormina.

I would suggest that you read a detailed guidebook of Southern Italy (such as Cadogan's), and research which locations have the best beaches. It will be easier, less time consuming, and less costly to drive from Positano (or take the train from Salerno) to a beach resort in southern Campania, than to fly to Catania (or Cagliari) from Naples.

Your itinerary does, nevertheless, seem a bit "out of balance", with insufficient time devoted to Venice (maybe you've been there already?), in comparison to time elsewhere.

GAC - I will go ahead and discuss it with the people going on this trip as to what they really want to see and do. I have been to Italy before but only in the Northern part. I would defenitely like to see Venice again even for a couple of days. Thanks for the information though :)