Grazie mille.

All of your suggestions are interesting. I'll call Lucca and Siena to know more about customs. Ancona seems to be nice to visit too. Maybe I could refuel in Corsica and then have a night in Ancona before customs.
As I'm not familiare with your ATC, do you think it's normal to transit overhead airports ? I'd like to plan flying straight this route at 4500 ft or 6500 ft: Corsica - Marina di Campo - Grosseto - Perugia - Ancona:

Do you think it's possible ?