Looking for some advice as we are planning a summer trip. Our plan is to be in Europe for 8-12 days (not counting flight days to/from Europe, just days in Europe for exploring) likely in mid to late July. The trip is a graduation present for my 18 year old step-daughter and her main interest is visiting Germany (she takes German and believes she'd like to live there at some point). It will be 6 of us, my partner and I, my step daughter, and then our friends who have a 5 year old daughter who loves to travel (they live abroad and travel multiple times a year). This is the first time to Europe for all of us and are looking for the general experience. We are not big drinkers, so not looking for any kind of party scene. Likely want to see castles, visit Dachau (or another concentration camp) (the 5 year old would not be along for this, we'd break into 2 groups) and experience the general culture in the area. We would maybe take a day trip to Salzburg as well if it would be worth it.
Based on my initial research, I think we would probably like to make Munich our main hub in Germany and then I initially thought go to Zurich as it's only a 3.5 hour train ride it looks like. However, the more I look into Zurich, I am not sure that is the best place for us to visit in Switzerland.
The research I did for Switzerland looks more like maybe Interlaken, Lauterbrunnen or Zermatt might be better. We'd like to see the Alps and the scenery, but my step-daughter is not big into hiking.
I'm looking for general advice and guidance as we start to plan, if it make sense to have Munich as a main hub in Germany, and then recommendations for best places in Switzerland and where we could fly back home from then. We would like to see as much as we can, but also don't want to put an itinerary together that has us overly rushed and not able to enjoy the trip. That's why I originally thought 2 hub cities may be best originally, but we are open to all suggestions.
If it helps, as a family, our last big trip was to Mexico and the family enjoyed our time exploring the culture and not the touristy beaches. My partner and I have also been to China and enjoyed taking a trip into the rural area and seeing the smaller towns/mountain villages.
EDIT: a little clarification on visiting time and the 5 year old will not be along for the concentration camp part of the trip