The mustard takes place at the Malakoffturm
here, also just a few steps away from the Pit Stop at the Lindt Chocolate Museum. Looks like this and the football are the two sides of the Detour, right at the end of the leg.
Two Roadblocks, one for rappelling at the Rheinstein Castle in Trechtingshausen, and another for the locks at Hohenzollern Bridge?
Still not sure where the costumes + horse takes place. Based on the windows in Lena/Morgan's and Rob/Corey's pictures, looks like the second floor of a conference hall?