Bonanno specifically mentions a guy last name "Parrino" during the Castellamarese war as a traitor to the family who Maranzano wanted dead... reading between the lines, Bonanno was definitely involved in this hit.
after becoming boss, he had an issues with Consiglieri Francisco Italiano, who famously opposed Bonanno during the family vote. He was whacked out. Fillippo Rappa, another Consiglieri, was demoted and whacked for similar reasons. of course, there were several others BEFORE the very bloody Bananas war. Bonanno was a hitter