Seb, you seem to be referring to the Ahmadiyya claims. These are largely based on hasty linguistic parallels—the same people identify the “Lost Tribes of Israel” in India, due to similar-sounding names. But in view of the limited number of sounds that can be uttered by the human palate, one would expect to find similar-sounding phonemes even in unrelated languages. (Similar reasoning is used in John Allegro’s book, The Sacred Mushroom and the Cross, which argues “Jesus Christ” to have been a code-word for a certain psychedelic mushroom, I kid you not.)
“Legends” cannot be assumed to be ancient, or to be true even if they are. Nicholas Roerich cites Tibetan “legends” about Christ, which on inspection turn out to be quotations from Notovitch and Dowling (i.e., then-contemporary esoteric literature). There are apparently some (medieval?) Islamic traditions such as you describe…but do they go back to the first century AD (as they would need to, in order to demonstrate anything about Jesus)? Of course not. They are no more credible than the similar legend that Joseph of Aramethea went to Britain. It is easy to IMAGINE Jesus going on such an adventure, but speculation is not evidence, and a hundred weak arguments do not add up to one strong argument. Anyway, if Jesus had made such a journey, a la Marco Polo, wouldn’t his followers have noted such a noteworthy accomplishment?
I’ve been to the tomb of “Yus Asaf” in Srinagar (which, by the way, is controlled by India—this is in reference to your complaint about “the fanatics that own that area now”), and beg to report that the caretakers were very nice. I’m sure there would be no obstacle to any legitimate research. As for the Vatican, you don’t even have to be Catholic to use their archives--but of course you can’t prove a negative, so there’s no way to be sure they’re NOT hiding secret files on Jesus, UFO’s, or whatever, in some secret room that no one ever sees.
You complain about the “official story” of Jesus, and yet, you follow it on numerous points which scholars find doubtful (such as the story of the magi). I suggest that the Ahmadiyya / Theosophical / New Age version is no improvement. There are numerous excellent books on Jesus Studies, by scholars who disagree with one another in various fundamental ways, but none of whom would project a post-Constantinian proto-Orthodoxy backwards onto Jesus.