barretthunter:
Unlikely as Christianity was spread by people who claimed to know him, including in Jewish communities and in Israel/Palestine soon after his (alleged) death. There is no reliable external (for example, Roman) evidence, but it just doesn't add up that the religion (or as it was often seen at the time, this new variant of Judaism) could be spread successfully among people who could easily have known if it was invented. Of course there were numbers of itinerant preachers at the time and it's even possible that a few stories about deeds or words got mixed in from them, just as I might "remember" person A saying something when actually it was person B.
As for the date, well, does it matter?
Not looking for a debate, but I'm not aware of any eye-witness accounts. More likely re-tellings of re-tellings. Your other points are valid. The teachings are based on something other than imagination, but reformer preachers were rampant at the time, the composite theory is very likely. Heck the mythology is based on Mithra so everything is based on something.
And, no, the date really does not matter.