Answer to number nine. Vito. Without a doubt. And, here is my rational.

Machiavelli was the most famous Consigliere of all time. He, first, worked for the Families that ran Florence then, after their defeat at the hands of the Medici armies, he wrote his most famous work "The Prince" in an attempt to keep his position under the new rulers. His gift, of a manual on how to take and maintain power, was accepted, and he was promptly exiled to the far north, where he lived out his life writing satirical theatrical works.

Now, I'm paraphrasing here but, as I recall, one of his most famous lines went something like this:

"There are two ways to rule a people. One is through love. The other is through fear. It is far better to be loved, because you can always become feared. However, once you are feared, you will never again be loved."

Vito was beloved. Remember when he asks Genco about Fanucci, and is indignant about how he preys on other Italians? And, later, when he kills him. Of course, he does it for his own gain but, it is also for the neighborhood. Nobody knows he did it, but word gets around, and everybody believes it. And, they love him for it.

Later, with the landlord, who has never heard of him, and with whom he tries to reason from moralistic-humanistic positions, to no avail. He tells him to ask around the neighborhood about him. Instilling fear. The landlord will never love him. But, the rest of the neighborhood will love him even more.

Michael? Only his direct family love him. His capos respect him and as, Tessio says "like" him, but love? Nope. And, most of his family dies, one after the other. Even his wife finally leaves him, feeling "no love" for him.

It was the dual trauma of Sonny's death, followed by that of Apollonia, that pushed him irrevocably to the dark side. Some might say it was the murder of Sollozzo and McCluskey, but I believe his love for Apollonia brought him back from the brink. She even made him laugh un-cynically (remember their driving lesson), but he never would again.

No more love. Only fear.

All that said, I have an eleventh question:

Where is the house that stood in for Don Ciccio's villa?