2. It's next to impossible to say what is or isn't likely about "the historical Jesus" because Jesus doesn't exist as a full character in any documentary or archeological source other than the various canonical and non-canonical Gospels;
Maybe as a completely knowable figure, yes. But the few "I am" formulations of John's Gospel where Jesus declares his identity with God have no equivalents in the Gospels which came before it. I take that to be fairly significant. For someone, especially a king of Israel or Israel itself to be declared a "son of God" had conspicuous precedent in the Hebrew Scriptures, and so the early Gospel writers calling Jesus the "son of God," especially accompanied by the added messianic and "Son of Man" attributions, is not that unusual. But John's very late first-century identification of Jesus with God looks to me pretty novel, and not traceable to any earlier traditions of what Jesus said about himself.
