okay, here are some thoughts on your north v. south puzzle:
the earth is a giant magnet and as such has the usual magnetic properties, such as magnetic poles. (the North magnetic pole is *very displaced from the geographic pole.) perhaps these magnetic poles place N/S by convention. another question to ask is in regards to the discovery of earth magnetism in relation to the cartography conventions.
I don't have any answers to these questions, it just seems that this might be something to consider....