The art museum in Girona is nice and of a manageable size, but I loved just walking around the large historic district. There are two historic churches as well as the walkable wall.
The jewelry collection covered by the Dali Theatre-Museum ticket is very near the latter and worth the time; 30 minutes or so should do it even if you want to try to take some pictures. The Theatre-Museum was larger than I expected and took more time than I had anticipated, partly because I had to adjust my path through the (multi-floor) museum due to the arrival of a French bus tour. I'd advise not waiting until you arrive at the museum to buy your ticket. I don't think they sell out really early, but even before COVID restrictions, individual time-slots were sometimes full. With your tight schedule you wouldn't want to be told you had to return in a couple of hours. Figueres is not that interesting a place to kill time, I don't think. However, I was told one can see the jewelry collection before the Theatre-Museum entry time, so that provides some flexibility.
It sounds as if you probably won't have time for Cadaques on your jaunt to Port Lligat, which is a shame. It's a beautiful white-cube former fishing village with bougainvillea everywhere. Perhaps your driver can give you a bit of a look at the town. The road between Figueres and Cadaques is lovely, incidentally.
In Barcelona I especially liked the Barri Gotic walking tour offered by the tourist office. The group was a lot smaller than the "free" tour groups I saw. The modernism and Picasso tours were also interesting. The Picasso tour is a way around the need to book your own tickets to the Picasso Museum. We got to the museum in the late afternoon and it was still utterly mobbed--think those scenes from classic movies showing cocktail parties in Manhattan apartments.
You can expect nearly all the Gaudi sites to be equally overrun. He wasn't the only fabulous architect working in Barcelona during the Art Nouveau period. There are two great sights by Lluís Domènech i Montaner. Be sure to include a visit to the Sant Pau modernista site where you can wander peacefully from building to building and be almost alone. The audio guide relieves you of the need to try to schedule a visit to coincide with the rare English-language tour. The tour of the richly decorated Palau de la Musica Catalana is a good way to see that building, also by Domènech i Montaner, but you could also buy tickets to a performance there.
The modernism tour offered by the T.O. included a brief stop at the commercially-run modernism museum in the Eixample. I'd have liked to have more than 15 minutes there, but it's hard to argue with a free look.
The MNAC on Montjuic was a 5-hour art museum for me. In addition to the expected paintings and sculptures there's a modernism collection (furniture, jewelry and decorative arts) and an impressive set of medieval frescoes from churches in the Pyrenees. The Miro Museum, also on Montjuic, is a pleasure to visit after the mob scene at the Picasso Museum. There are of course many other museums in Barcelona.
I spent several nights in Toledo and don't know how well it would work for a day-trip, but I got great value out of the little bracelet that provides entry to a bunch of secondary sights of historical and architectural interest. Many of them had bilingual tours offered twice a day, which I found interesting. It wasn't easy finding my way from place to place to fit with the scheduled tours, but I have since discovered the great value of the You Are Here dot on Google Maps. Toledo has a huge, somewhat hilly, historic district, so you wouldn't go wrong by taking a do-it-yourself approach there and just stopping in at a few places suggested by your guide book.
I wouldn't try to cram Cordoba into this schedule. There's a lot more to see there than just the Mezquita.
