With the help of Italia dei cognomi, a database of Italian surnames, Pagine Bianche (The White Pages), Google and some emails I was able to draw a map of distribution of De Bastiani in Italy.

As soon as the site was ranked in Search Engines (keywords "de bastiani" or "debastiani") I received some emails from people having the same family name.

My grandfather Antonio Michele lived in Feltre, province of Belluno. This is an answer to whose who asked me where my family comes from, even if I never lived there.
I currently live in Parma, after having resided in Udine and Bologna.

De Bastiani is quite rare. The cradle area is probably Cesiomaggiore or San Gregorio nelle Alpi in the Belluno province.