Hey there, I'll give short and sweet answers, I'm sure very soon someone else will go into more detail and probably correct the things I have to say.
1- Johnny Pops was a capo, Hamilton fell under the power of Buffalo, he was the "boss" in the sense that the actual boss was more of an absentee landlord. In terms of his strength in ranks, I have no clue. Nor do I think anyone really does except the cops on that beat.
2-Paul Volpe, the Fox, he was an interesting man. There is a link to a documentary on him on my Topic called Toronto Mafia. It'll answer all your questions.
3- It was an offshoot, until Vito Rizzuto's man in New York was murdered on the orders of Massino, things began to drift after that. Some say the recent violence has been New York trying to drag the organization back under its influence. I mean they offered Vito the position of Capo. Vito Rizzuto. A Capo. Its almost insulting, considering the power he held. He refused, continuing his defiance. It would make sense, Montreal gangsters have been seeing far more success than its counterparts in New York.