Quick question, what's the function of the five huge grey rings on the galactic map that go around the edge? Are these supposed to be measurements of distance or a scale value? Do they determine an area or something?
You are entering the vicinity of an area adjacent to a location. The kind of place where there might be a monster, or some kind of weird mirror. These are just examples; it could also be something much better. Prepare to enter: The Scary Door.
Thats a canon mark I believe, in canon alot can be told about the system by its distance from the center of the Galaxy. From this view comes classification of various regions of space such as rims: inner, mid or outer ( and Expansion region between Mid and Outer rims)
They aren't markers of the various regions. Those are perfect rings, and the markers between the regions are wavy lines. If you look carefully at the sectors, you can see the decisions between the regions. Go to wookieepedia for help if you need it.