I doubt and the murder of Vito's son was "unrelated" to Mob business. More so considering Magi is a suspect and has mob ties. Maybe Magi didn't have anything to do with the other murders and more people got on board with the plot after the murder of Nick Jr but Magi would have had powerful people behind him with ulterior motives IMO.
I think he was secretely supported by at least Tony Mucci. One of Magi's bodyguards shared a residence with one of Mucci's bodyguards. I think it was a test to see how the Rizzutos would respond. In any case, the murders of Del Peschio and Nick Jr. are unrelated as the murders of Cun trera and Nick Sr. were organized by other individuals.
"It was between the brothers Kay -- I had nothing to do with it."
