Are the lower and upper paths connected? It's hard to see on Bing's images.

According to Bing, there is a street missing here

Is there another shop besides Hagebau Dreyer? If so, add it, if not, remove the landuse area since it is not supposed to be used for single shops.

Several streets or service highways missing

several unconnected ways

Connect the paths leading to the parking lots to their corresponding roads (several cases, this is an example position)

Is Zur Warte really connected to Kasseler Straße? According to Bing, there are a lot of buildings in between there, not leaving any space for a road to pass through.