I will agree with the others—-you have all your time in cities and none in a typical Swiss mountain village. That is the best way to experience the culture and enjoy the scenery. So I suggest you substitute the car-free village of Wengen for Interlaken. It is just a bit further on the train, but so much more charming.
Sam has a great idea to stop in St. Gallen on your way between Munich and Switzerland. Spend a night here to experience Appenzell. Then take the direct train to Luzern for 2 nights, then the scenic Golden Pass railway to Interlaken and change to the train bound to Wengen (via a change in Lauterbrunnen). Two nights up there in a charming (but not all rustic) hotel such as the Maya Caprice. Maybe ride the cablecar up to Mannlichen and a gondola down the other side to Grindelwald to walk around there. No hiking required.
https://www.mayacaprice.ch/
https://www.maennlichen.ch/en/summer.html
Of course there are other very nice hotels in Wengen (so that people have trouble choosing), and other activities on offer; I just mentioned these as a starting point.
People recommend Wengen over Lauterbrunnen for a short stay like 2 nights, because Lauterbrunnen is a very busy town down in the valley, full of traffic.
From Wengen head to Bern for a night or two, depending on your interests. This city has a lovely Oldtown area and we find it more appealing than Luzern (but we are in the minority). So maybe you will be convinced to spend more time in Luzern and less in Bern. It’s all good.
You can reach Zurich airport by train in just over an hour from Bern, so it is possible to skip Zurich altogether. But if you have the time you can make Zurich your last stop before flying out.