After Munich you should go to Regensburg and visit the old Town. For a specific christmas market I would suggest the most famous one in Nürnberg. Instead of Würzburg go to Rothenburg ob der Tauber (one of the few cities where the whole medieval city wall is still intact). An alternative to Frankfurt which is great for museums is Wiesbaden and Mainz. In Wiesbaden you can visit a very nice christmas market (opens on November 28th). In Mainz you can visit the Gutenberg Museum (the inventor of modern book printing and see one of the first printed bibles). Since you have only 9 days you should be careful not to pack too much into the trip otherwise you will have only a day and a half in every place.