I don't think Genovese wanted to make himself boss of bosses, the previous two gentlemen who tried that wound up dead. While Vito's a ruthless prick, he's not exactly stupid. I think '57 was vito trying to throw his weight around; because while there never was a boss of bosses after '31, there was a consistant unofficial pecking order on the commission depend who had the power and who had the right allies. I think Vito was trying to call a commission meeting to show that he was the man in the drivers seat on the commission now which then gets wrongly interpreted as trying to make himself capo di tutti capi. Bonnano talks in his autobiography about the changing tides of alliances on the commission during this time peroid. Maggadino and Bonnano did have a falling out (this is covered also in joe's book, he clearly does not like his cousin) which I think played a big part in the meddling by other families that lead to the banana's war (although I don't think anyone every believed for one second that joe's "disapearance" was a kidnapping by maggadino)

I think Vito made himself boss of luciano/masseria family and they officially named gambino head of the mangano family at the '57 meeting to put the costello/genovese and mangano/anastasia beefs to bed.

The sicily thing is interesting, there's always talk of that being where Bonnano set up a major heroin deal, he may have, but I think there are arrest records of made guys that indicate that these guys were smuggling and selling heroin long before 1956. Bonnano may have expanded it at that point, he didn't necessarily need lucky because bonnano probably had more contacts in sicily than lucky did because of his lineage.