Ahh...the Nazereth angle. This was covered by either cj.23 or dr kitten a while back. IIRC, there is plenty of archelogical evidence that places Nazereth during the time frame of the gospel story. To me, it's one of the weakest arguments against the validity of the gospels.
I agree that it's not something on which the overall truth of the NT would actually depend, but it seemed a reasonably logical starting point. I'd be perfectly happy to start with something else as consensus dictates.
As far as Nazareth is concerned though, my understanding has been that although it was there at the time the NT writers said it was, it was at best an insignificant settlement of only a few families.
As such, it does not fit very well with the descriptions implicit in the words of the authors of the NT.
Luke1:26-27
And in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth, To a virgin espoused to a man whose name was Joseph, of the house of David; and the virgin’s name was Mary.
Luke 2:3-4
And all went to be taxed, every one into his own city. And Joseph also went up from Galilee, out of the city of Nazareth, into Judaea, unto the city of David, which is called Bethlehem; because he was of the house and lineage of David.
Matthew 2:22-23
But when he heard that Archelaus did reign in Judaea in the room of his father Herod, he was afraid to go thither: notwithstanding, being warned of God in a dream, he turned aside into the parts of Galilee: And he came and dwelt in a city called Nazareth: that it might be fulfilled which was spoken by the prophets, He shall be called a Nazarene.
Luke 2:39-40
And when they had performed all things according to the law of the Lord, they returned into Galilee, to their own city, Nazareth. And the child grew, and waxed strong in spirit, filled with wisdom: and the grace of God was upon him.
Not damning evidence of malfeasance, certainly, but at least an indication that the authors were willing to take liberties with the truth should it suit their purpose.
And the above words must also call into question any description of Luke as 'one of the world's greatest historians'.