Ok, here's how I got myself oriented.
As I went about discovering the DysArc I made the image below, a schematic
view of the Arcade as seen from directly overhead.
Each cube is an Arcade room or specialty area and the sphere is what I call the central Exchange because all the rooms connect to it directly no matter what else they do.
Now I've made the image into a map you can use to explore the Arcade. Click on the cubes and sphere to find out what I've found out so far.