Thanks for the info DVD, I remember hearing similar information in the Nooma video on Discipleship, which I highly recommend, because I remember it having a lot of very interesting information about Jewish customs, much like you have provided.
So it seems like some strong evidence points to the fact that disciple were likely young men, younger than 20 (except Peter) and probably older than 13. I think Rob Bell suggested they were in their late teens because other Rabbis had passed on accepting them as disciples, and they had likely given up the idea of following a Rabbi until Jesus called them. Either way, it seems kind of harsh to say that the fellow's youth leader is clueless, which doesn't really seem polite at all...
Anybody have anymore information or insight about the Disciples' age?