In my opinion, the four directions do not have four separate meanings. I think that the only direction that really has a specific significance is the east. The east represents knowledge and the ways of the past (when the people were much more technologically advanced). The east is the forbidden direction. To me, it is like the tree in the Bible story of the Garden of Eden -- it is the direction of an important knowledge that is in some way dangerous.
The other directions are all like one another. They are good places to hunt, we are told. They are the normal world where people live and there is nothing particularly special about them.