Hello Bosuncat
I did this trip last September. In Barcelona you get a walking tour of the Sagrada Familia for about an hour and then a two hour coach tour. You then get let loose on Las Ramblas for a couple of hours. Most people walked up and down in groups.
The optional excursion to Figures and Rosas I cannot tell you about as it was cancelled due to lack of support.
Gerona was a lovely old town, we got about 2 hours there which was long enough to see everything as it is a small centre.
The hotel was lovely, I had a room facing the hotel opposite but was not bothered by noise, all music stopped before midnight. There was no noise inside the hotel.
Food:- There was a very good salad bar each evening and a good choice of cooked food. The deserts were excellent but I guess you won't be having those.
I never used the spa as I didn't know it was there until halfway through the holiday. I went down to look but it was closed. There was a table for massage and a small gym and a library. Didn't notice a pool but that doesn't mean there wasn't one.
This was a nice relaxing holiday with the beach just across the road from the hotel. A boat to Tossa De Mar goes from about 100 metres up the beach. This is a nice day out.
I think you would be OK as I didn't do a great deal of walking.
Sandra