We will be traveling to Germany at the end of March for a seven day trip. We will be flying in and out of Basel. Considering Freiburg, Baden-Baden, Rothenburg, Munich loop. Suggestions will be greatly appreciated!
I think, considering your starting point and the number of days, you should scale down the range somewhat. Baden-Baden, Rothenburg, and Munich are too far away. Freiburg's ok. Consider Titisee, Triberg, the Schwarzwaldbahn, Singen, the Bodensee area, Sigmaringen, Colburg, Switzerland.
Or into Alsace