Well, yes, all true, but it also depends on what concerns you. If you're a Christian trying to get to know Christ more by analysing his earliest depictions, then perhaps, focus more on his message. Maybe even more than the question of his literal existence, focus on his message. Probably. A person's relationship with their god is their own business, of course.
If you're interested in history, including art history and how religion and art feed into one another, regardless of your personal beliefs, then there's much of interest to be gleaned from things like how Christ has been depicted in different cultural contexts. I'm a bit rusty on these things, but I know there are early depictions of Jesus as a swarthy, dark haired, dark eyed gentleman, as one might expect a man of his heritage to be. But there are more recent depictions of a fair Jesus. At some point that must have made sense to someone, and others ran with it. That's something I find interesting. There are obvious reasons why it makes no sense, but they're not as important as that your saviour be depicted conforming to your culture's ideals of beauty. While that may seem shallow, in a sense it's the opposite, using an artistic representation of the physical to reflect the beauty of the spiritual.
I'm a bit rusty on this but I'm sure I've heard somewhere that some of our earliest representations of Jesus depict him as a beardless youth with curly blond hair, somewhat in the manner of Alexander the Great or Apollo. This is also interesting, but I've no idea where I heard that, and therefore can't verify it.
However, I'm pretty sure the very earliest depiction we have is a graffito of a man worshipping a donkey headed man on a cross, which was specifically intended as a jokey insult to a specific Christian guy. We can read from that that the one guy in a group of people who has crazy beliefs is someone mocked behind his back in any period of history.
