You brought up Gilgamesh existing in relation to the idea of the Jesus Myth. I pointed out some legendary figures and you respond by saying they aren't related, that the existence or mythicism of one is unconnected to the other. I agree. It has no tendency to prove it either way.
Socrates was mentioned earlier in the thread. The interesting thing about Socrates is that the quality of his ideas are completely independent of his existence. The same cannot be said for a religious figure.
I don't think it's correct to say that Christianity started as a purely jewish movement. None of the original gospels were written in Aramaic, nor were the Epistles. Paul himself was asserted to be a Roman Citizen. The gospel of Mark was written in greek and believed to have been written in Rome. I don't see how it can be suggested that it was a purely jewish movement. Moreover while modern historians generally accept the historicity of Jesus they don't accept the gospel of Mark (from its wikipedia page):
The modern consensus is that Mark's purpose was to present a theological message rather than to write history.
So what can we know of a historical figure from a writing that is itself myth? Whose purpose was not history but religious instruction.
Even were it written in Jerusalem it is wrong to suggest that would be a purely Jewish movement without Greek and Roman influence. At the time of its writing it was a province of Rome.
I have heard the argument about the inconsistency of the character as being a basis for there being an historical Jesus. Christopher Hitchens does quite a good bit on it. For my part I am not convinced that the inconsistencies in the story are great evidence of historicity.
I take issue with the suggestion that there were near contemporary writings about Christ which accepted his existence. The passage in Tacitus, is neither contemporary (it is 100 years later - John Frumm and Ned Ludd were both believed to be historical in a much shorter timeframe than 100 years and both after the existence of the printing press) and does little to prove his existence. There is no indication in the passage that Tacitus was doing any more than echoing what Christians in Rome were saying. He certainly does not appear to refer to any imperial record of his existence or execution (I don't subscribe to the theory that we should have a roman record of his execution). The most important thing about the passage in Tacitus is that it shows that by that time there was a Roman community of Christians.
I also think it is wrong to think that people of the time would have been concerned if Jesus was real or not such that a refutation on that basis would have been recorded. At the time there were religions which to the uninitiated referred to real people but were revealed to be parable to the initiates.
I think the writing of Josephus has its only problems, not the least it has been tampered with.
Again I am happy to accept, particularly with historical figures, that absence of evidence is not evidence of absence. I do think there is a problem with the idea that there is nothing unusual in there being little evidence of an itinerant Jewish preacher. If the Gospels or the Pauline Epistles record anything of his teaching or anything about a real person that teaching must have made a substantial impact on his followers. Otherwise it is unlikely that there is any reflection on the historical character in the gospel. The fact that any jewish preacher was crucified by the Romans does not prove that he was the spark that ignited Christianity. Even if there were a jewish preacher who was a follower of Rabbi Hillel crucified does that mean real Jesus?
The absolute proliferation of heresy in the early Church has always struck me as unlikely if the leaders of the Church could actually fall back on a received teaching or direct knowledge of Christ. However as much respect is paid to Paul who simply claimed 'inspiration' and 'visions' of Jesus.
In the end I don't think it's a question that can be definitively answered but I do think it is an interesting one.