Plan B: Making a new itinerary to include Switzerland

Are you sure about the 2 nights in Zurich? Is there something special that you had in mind to see there? I would have to say that I would pick somewhere else for those two nights and just do the airport hotel the night before you leave.

I have stayed in the Hotel Alexander in Zurich. Pros: Air Conditioning and convenient location to the train station. Small supermarket right next door. Cons: The street below is party central with loud noise-making people all night. If you had a room at the back of the hotel, it might work. Having a room right above the street was not conducive to getting any sleep for me. If noise doesn't bother you, it might not be an issue.

From one retired Carol to another:
I appreciate your concern about Zurich. We stayed in Zurich last year at the beginning of a Road Scholar Tour, and was pleasantly surprised at how much we enjoyed the city. I like walking around the lake and window shopping on Bahnhofplatz. And I want to spend more time at Uetliberg, overlooking the city.
Thanks for letting me know where you stayed. Our hotel last year was lakeside; a bit far from city center and the train. I'm not sure where I want to stay this fall.

Stein am Rhein does not have the same vibe as Appenzell. The town itself is very cute, but there is very little to explore around town, unlike in Appenzell. I'd rather spend those two nights in St Gallen, actually, and visit Stein am Rhein as a day trip from Zürich, where you should stay 3 nights - no need to stay at the airport, which is 15 minutes away by train.
As for Chur: optional to me. The historical center isn't bad, but I'd rather spend a 4th night in Pontresina, personally.

Balso: I appreciate your recommendations A LOT! As I said previously, haven't made any lodging or airline reservations. Time is somewhat flexible. Just booked 3 nights in Varenna; so our time in Italy is more concrete. But the Switzerland part of the trip is tentative.
We really liked our stay in Appenzell last year, with a trip to Ebenalp, so probably would have been disappointed in Stein am Rhein. We'll do it as a day trip. What about Rhein Falls?
Pontresina: Had not even thought much about the area until it was mentioned so often on this Forum...and read Pat's positive, report of the area. I love the Lauterbrunnen Valley, and Mürren. Would Pontresina have the same feel...with mountains surrounding the area?
Chur: Will have to think hard about skipping it. Just read that the "fictional Heidi-land" is 10 miles away by bus. Growing up in Hawaii, reading Heidi,... well, Switzerland seemed so magical and so far away.
If we stay in Zurich another day, we could even make a day trip to Luzern...to see the Chapel Bridge again (stayed there 3 nights last year, when weather was not ideal in the city).

The Rhein falls are really underwhelming, I find. The volume of water is high but the height is very low.
As for "Heidiland": I have not been, it seems like a bit of tourist trap but of the fun variety, so why not! In that case, stay in Bad Ragaz rather than Chur. There is a very good thermal spa there too.

Thanks balso: Will skip Rhein Falls. And we can skip St. Gallen. Visited there last year and went to the library at the Abbey, and saw the "red zone;" very unique. But not our favorite city either. So now will have to rethink time after Pontresina