You can add Poland (Warsaw and Krakov), Zagreb, Belgrad, and Sarajevo.
In Swiss, you do not want to miss Interlaken. Inn*****ruck in Austria you may want to add, too.
Too many places, you may need to be more efficient to cover all, or cut some "2nd class" places.
Tang07059 went to that area, and may have good experience. He is very experienced in driving cross Europe.