Barb,
I'm so glad you came on the RS Forum. Several of the people answering you were in Switzerland last year, including my husband and I, as well as others who are "experts" on Switzerland. I love Switzerland so much that we are returning this fall, for our 4th visit.
Last year we were on a Road Scholar tour, chosen because the itinerary included the Glacier Express, which we started in Chur, heading west. Chur is okay...but given the choice of a night in Chur or in the Lauterbrunnen area, I'd definitely choose Lauterbrunnen. Also, as "scenic" as the Glacier Express route was, it doesn't compare to being out on a trail, surrounded by mountains as you would be in the Lauterbrunnen area...or seeing the mountains from your hotel. On the Glacier Express, we were in reserved seats, so we didn't have the luxury of moving from one side to another. And it was difficult to take pictures through the windows, unlike some of the regional trains, where you can open a window.
We used to live in Cheyenne, Wy. and made frequent trips to Rocky Mountain Nat'l park, even camping there, but the Alps are so much more impressive because they appear closer.
Since you have now made the decision to fly in and out of Zurich, traveling by train is most convenient. The train station is right there at the airport....across the street from arrivals, and down a flight of stairs. Basel is just a short ride away.
And from Basel, it is so convenient to head to Lauterbrunnen. We did that last year. We chose a departure time where the end destination was Interlakken Ost ; got off for an hour or so to have lunch and then took the train to Lauterbrunnen.
At Lauterbrunnen, you have a choice of choosing lodging in the valley itself, or to one of the "car-free" villages on either side; Mürren or Wengen. Do not stay in Gimmelwald...even tho it is Rick Steves' favorite. Great to visit...but not stay; too small. Here, you will find people passionate about either Wengen or Mürren, or the convenience of staying in the valley, Lauterbrunnen. There are majestic easy hikes on the Wengen side as well as Mürren side. (I'm not going to make a case for my favorite hotel in Mürren, Hotel Bellevue, with fantastic views from rooms with balcony).
Balso had a great suggestion of taking the Luzern Interlaken Express, which is very scenic.
If you still want to spend time in Zurich, to tour the Lindt chocolate Factory, Zurich can be enjoyable. Here people have "mixed opinions" about Zurich. We like it. I like strolling along the lake; walking Bahnhofstrasse, going to Uetliberg.
As Pat mentioned, the train system is so efficient, especially with a Swiss Travel Pass, that it doesn't make sense to rent a car, and deal with parking, etc. The key is to "pack light;" preferably 21" suitcases that are easy to maneuver on and off trains. Besides, rooms can sometimes be tiny with barely enough room for (2) 21" suitcase.