I don't see the point in policing whether he is referred to as Christ or Jesus from Nazareth - is there some meaningful distinction here?
Also documents are not scientific evidence. The documents are enough evidence to consider it a historical fact, but that's, again, not the same thing as a scientific fact, and it is not backed with any material or physical evidence. Not that we expect or demand such evidence, I'm only pointing this out because you claimed there is scientific proof where there is none.
Regardless, I would be curious to get your receipts on those documents referencing Christ that predate the gospels, I hadn't heard of that before!
Speculation about the resurrection being faked with sedatives is irrelevant to this discussion, but since you brought it up, why not entertain more likely alternatives: towards the end of the book of John, Mary saw the resurrected Christ in the tomb and was the first to see him, yet she did not recognize him:
“They have taken my Lord away,” she said, “and I don’t know where they have put him.” At this, she turned around and saw Jesus standing there, but she did not realize that it was Jesus.
He asked her, “Woman, why are you crying? Who is it you are looking for?”
Thinking he was the gardener, she said, “Sir, if you have carried him away, tell me where you have put him, and I will get him.”
If he took sedatives, why did he look like a different person such that she thought he was the gardener? Why not think the resurrected person was just falsely claiming to be Christ, since he didn't look like him anyway? Why resort to more elaborate explanations when we have more simple ones at hand?
There is also the issue about how Christ supposedly survived being eviscerated and tortured before being hung on the cross, even if he did have access to sedatives. It's just not likely he survived that, and the sedatives don't explain that away.
Eh, ironically it's the Lutherans who still believe in transubstantiation, which means communion is not a metaphor and the essence of the bread turns to Christ's flesh and the essence of the wine turns to Christ's blood, the cannibalism is more literal for Lutherans than some denominations.
Either way, Christ could have qualified his statements if he was speaking in metaphors, as he does in other passages, but he was strangely literal about eating his flesh and blood, and again that whole chapter reads like Christ was wanting to alienate his followers because he had amassed a crowd that he didn't want to deal with.
And yes, lots of scripture is interpreted as not having a literal interpretation, that everything has hidden and layered meanings. This was used a lot by Christians to re-interpret the Hebrew bible as foretelling Christ as the Messiah, and before Christ the priests and interpreters wished to breathe life and meaning into scripture by finding meanings in there that weren't supported by a more literal or direct reading. Still, this seems like addled religious thinking to me, strangely disrespectful of the scripture and motivated by a need to resolve cognitive dissonance when passages don't make sense or contradict something the church wishes to change their minds on (such as the way the Roman Catholic Church re-interpreted Christ's messages on poverty and wealth).