Given that the ability to write was an unusual skill in the time of the composition of the Gospels, would Mark have been likely to have been a scribe? I mean if the tradition of Peter dictating to Mark is true, would Mark have had professional training in acting as an amanuensis?
I am having trouble finding citations for this, so maybe some of the more erudite members of this list can help me out, but: I have read from a few sources that Mark's spelling, grammar, and overall Greek style are just about at the bottom of the barrel of the New Testament, a spot probably shared by Revelation. This being the case (and I'm assuming it is, based on my memory, not on any citations I can find readily available), I doubt that Mark had any professional training at all. I would guess that he was someone who had to have to some kind of minimal literacy in order to fulfill whatever professional role he may have had -- some kind of business proprietor, or a low-level government functionary, or ...