Sounds like an incredible trip! If you are going to Switzerland, Interlachen is a must see -- more specifically don't miss the Jungfrau railroad trip. It is incredible. You can hop off the train and visit Alpine villages along the way.
_ Jungfrau region Switzerland guide and
_ Jungfraujoch Jungfrau railway train rail trip Switzerland guide trip.
I spent 3 weeks in Switzerland while my husband was working there. On weekends we would hop a train and just "go" - no specific destination in mind, it was a remarkable adventure!