As our friend Steven would say, his name would have been Yeshua, or something very close to this. "Christ" is a title, not a surname, of course, being the Greek equivalent to moshiach, meaning "annointed". His real name would then have been something like Yeshua ben Yosef.
As far as being of the tribe of Judah, that seems most likely, since they predominated in the southern kingdom. But by this time, with the exception of the Levites there were no real tribal affiliations remaining. Since some members of the 10 northern tribes had come south prior to the destruction of the northern kingdom, it is likely that most Jews at the time were of a mixed tribal background, with Judah predominant.
The assignation of Nazareth as the hometown of Jesus is problematic. Many scholars think that the proper expression is "Jesus the Nazarene" or "Jesus the Nazirite" referring to his political/religious affiliation rather than to his hometown.
Thanks for all the info.any thoughts on the Karaites?
They claim, of course, that they are the original Jews, but objective history suggests that they emerged in the 600-700s as a reaction against rabbinic Judaism. If you are interested in learning more about what they believe, check out http://www.karaite-korner.org/index.shtml.
Gotta run. I'll get to the rest of your post later tonight.