Has anyone taken one of the hiking trails down from Merkur Mountain and ended up in another village? How did you get back to Baden Baden?
As I remember there is bus service between Baden-Baden and many of the villages.
Here is the "map" of the bus lines in the area. Note: Buses 204/5 go to the Merkur Bergbahn.
From looking at schedules, I would say you better hike down to the north, to Ebersteinberg, or to the south, to Oberbeuren. Those villages both have buses directly back to Baden-Baden. If you go east to Staufenberg, you will have to take a bus from Kirchstrasse into Gernsbach and another from Gernsbach to Baden-Baden.