Your trip sounds wonderful, but I am curious. Why are you starting in Rome, making your way up north to Venice, only to have to go WAY DOWN SOUTH to Foggia from Venice? That's really far! Why don't you start up north, and make your way south? I would recommend ending in Naples and then going to Roseto Valfortore/Foggia (about 50 miles NE) from there. Naples is a beautiful city, with lively people. The surrounding areas (Amalfi Coast, Sorrento, Capri) are magnificent. If Naples is out of the question, make Rome your last stop before taking a train from Rome to Foggia, and then a bus to Roseto Valfortore. Buon viaggio!