The "crust" of the Dyson Sphere is going to be 50 miles thick, then has a molten layer which is 10 miles thick. The molten layer moves in a constant circular motion and basically help similate plate tetonics, volcanoes, earthquakes, and the such, but also renews the rock as well. After the molten layer there is the crystalline computer system that has direct control over everything with the Dyson Sphere. It is about 2 miles thick which stores all the programming, the "souls" of sentient life, and regulates the sun and weather of the Sphere. It also controls the "magic" for it has direct control of the nanite systems that allows magic to exist. Beyon this layer is the Dyson Sphere superstructure and defense systems that protect it and shields it from any outside intruder.