I did this tour as a young senior and will probably do it again 10 years later. This is not a hiking tour per se. Hiking is up to you. I stroll. Salzburg - lots to see that is not remotely oriented to hiking. Dolomites, well, if you do not want to walk, Bolzano is a great town to visit. Fuessen, likewise - not to mention the castles. I especially enjoyed my lakeside lunch in Schwangau. There was a community concert one night we were in Fuessen. Lauterbrunnen - if you do choose the flat valley walk, you can take the lift at Stechelberg to Gimmelwald and enjoy the sites from the Pension patio. Wengen is kinda cool to visit. Nice little train goes there. Enjoy a lake cruise in Interlaken. Chamonix - everyone (or so it seems) heads up the Aiguille du Midi cable car.
I loved this tour - hence thinking about repeating it. It can be very relaxing - note the bus rides between locations. You reach your destination in the afternoons, check-in and get your bearings, stroll around and figure out how to spend the evening. It is the following day (or two in Lauterbrunnen) that you have substantial walking potential, and it really is up to you. One of our forum members has written and published some books on easy hiking in both the Dolomites and the Berner Oberland. Check her out on Amazon. She explains the difficulty of walks along with transportation options and things like where to make pit-stops and refreshment breaks.
If the itinerary and locations appeal to you, I am sure you will find enough to keep you interested. Note, somewhere in my readings, I recall Rick Steves telling us that the swiss use seniors to mark the approximate length of time to get from place to place on trails. Well, I am slower than swiss seniors, it seems - but it is all so beautiful, I did not mind.