Will be traveling with the RS tour in July with a mildly active 78 year old. Noted that some days have up to 6 miles of walking, etc. which may be difficult. Has anyone been on this trip and can advise if there are options should one not be able to complete the entire day?
I have not been on the Switzerland tour, but on the tours I have taken there have usually been options for those who don't want to walk as much. It looks like many of the actual hikes are optional, as were the more strenuous jaunts on tours I've done. Have you checked out the scrapbooks from 2016? #2 and #22 are the Switzerland tour and offer a more personalized review of the trip.
https://www.ricksteves.com/tours/scrapbooks
Everything is optional on RS tours. You can always opt out of a group event if something else interests you or you think something may be more rigorous than you were hoping for. Just let your guide know in advance.
For example, the big hiking days are likely to be in Murren. If you don't want to do the group hike, you can always ride the cable car to Gimmelwald, or all the way down to the valley floor and go to Trummelbach Falls, or go down to the valley and then up the other side to Wengen, Kleine Scheidegg or the Jungfraujoch. Lots of alternatives to choose from.
P.S. I'm on the July 17th Switzerland tour. I've been to Murren and Lucerne before and am really looking forward to returning.