“In the German context does a verbal agreement have the same value – binding character – as a written agreement?”
In the German context there is no higher level of commitment than making a written agreement. The written word in the German culture is extroardinarily binding. It is a reason why Germans are so careful about signing their name to an agreement.
A verbal commitment has almost as high a level of commitment – binding character – as a written agreement. In general, as a culture, when the Germans say and/or write yes, they consider themselve to have given their word. It is binding. And not in the American sense of different levels: 98%, 68%, 38%, 18%, 8%, even -8% and so on.