January 2024 Itinerary - Seeking Help and Advices

First thing to mention: Harder Kulm is closed in winter until end of March. Interlaken itself is not really worth visiting in my opinion, especially on a one week trip. For day trip and excursions, it helps to know what your interests are and what you’re hoping to see and do in Switzerland….museums? Chocolate? Nature? Skiing, sledding and other outdoor stuff? Kid friendly activities?
Speaking of activities and day trips: using public transportation on your own is easy and efficient. Switzerland is very tourist friendly, well organized and plenty of info available in English. I wouldn’t waste money on Get Your Guide packages.
Others will probably have more to say re destinations, train passes and scenic route recommendations. In my opinion: There are regular trains running on the same lines and they are covered by a Swiss Travel pass, no reservations needed. Schedules are on www.sbb.ch/en Unless you really want all the bells and whistles (and don’t mind the accompanying price tag) just get a rail pass and ride the regular trains. If you have kids under 16, they travel free with parents who have Swiss Travel passes with a family card. You don’t need to book regular trains in advance, you just show up and get on with your pass or ticket.
Shop hours are generally more limited than the US. It also depends where you are - for example in Zurich things are open until 8pm, in Luzern they close at 6:30 or 7pm weekdays and 5 on Saturdays. Sundays most shops are closed everywhere except at train stations (larger stations also have extended shopping hours all week) or tourist oriented things.
And just another word on January - just fyi, school vacation ends Jan 7th for Swiss cities, which may affect hotel prices and crowds at ski areas. Also, January weather is usually pretty gray and blah in the cities. Many people head to the mountains on the weekend to see some blue skies so just be prepared for more crowds if you’re in the mountains over the weekend.

What is your family make-up (number and ages)? That may guide whether to get Swiss Travel Passes. How do they work? Just board the train and go where you want and show your pass when the conductor asks. Named tourist trains like the Bernina Express or Glacier Express require purchased seat reservations not covered by the Swiss Travel Pass. Also, the STP only covers trains/buses/cable cars to inhabited villages. Tourist points like the Jungfraujoch cost extra, but the STP gets you a discount.

The named tourist trains are just special trains that operate on the same routes as regular trains. These are at least once per hour. If you want to hop on and off, use these trains which are less crowded, don't require expensive reservations, and have the same scenery available to view.

We did Pontressina to Murren. It was a six hour train day, but comfortable . I'd suggest spending time in Murren and/ or Wengen instead of Zurich. You can then depart from Lucerne. The train from Lucerne is 1+ hour and goes directly into the airport.
Review the posts under the Swiss section . I'll attach my 2021 Trip Report- perhaps there will be some helpful info.
Safe travels!

https://community.ricksteves.com/travel-forum/trip-reports/lucerne-62eb4d28-60ab-4837-b4b4-91a2486eb732