I'm guessing yo haven't read the book since you put it here and not in Other Puzo Novels

1. Skannet dies and Cross gets aligned just right in every way. Domenico was a smart man in all means. It was also done in a way that not regular thugs would've done it.

2. Because Domenico and his sons knew that Cross and Dante had their feuds. All of a sudden he isn't to be found and one of his Villas gets burned down, there's no such thing as a coincidence.

3. In the book it really shows how Domenico doesn't want Dante to go through the rough life. He is his favorite even after all the hate Dante has inside of him. Pipi killed his father, Dante killed him and Cross killed Dante. In other words, revenge is a bitch.