Tim welcome and viaggio pass?

[Eds]

I'm going to italy in January and was looking at getting a tim sim on the welcome offer they have there, just a little confused with their website and have a few questions.
With their welcome offer it only lasts 30 days which is perfect for me cause I'll be there less then that. but I'll be leaving italy and coming back during that time, can a viaggio pass be added to this offer? Also does it count up 7 days from the moment you use this viaggio pass or is it 7 days in total? Also can I add more then one of these viaggio passes? I only ask cause I'll be italy on and off
Starting with 6 days italy, 1 day monaco, 5 days italy again, 3 days Greece, 5 days italy again including San marino, 5 days France, and back to Italy 1 day.