We're just getting started on a 10-week visit in Spain, so don't have anything to offer for your initial question. But we spent 2 fabulous weeks in Portugal this past fall, so I've got some tips for that!
During your week in Porto, make sure to take a day trip into Douro Valley port wine country. (You can spend some major money on small-group tours, but we were quite happy -- and saved quite a lot -- by just taking the train to Pinhao (it clings to the riverside and has stunning views the whole way.) From there, we had booked a two-hour "rabelo" boat tour," which takes you deeper into wine country. Upon returning to Pinhao, we then visited Quinto Do Bomfim for a tour and tastings, which is a short walk from the rabelo departures and the train station. There's a lovely spot to enjoy a meal and/or "mas vino" between the riverboat landings and Bomfim, The Writer's Place. Lovely terrace overlooking the river! It was a long day but soooo worth it!
Another worthwhile daytrip from Porto is to take the train down to Coimbra. (One hour each way.) It's home to the oldest university in Europe, with a stunning library that supposedly inspired J.K. Rowling and views over the river and countrysidew that are jaw-dropping. We just had a five-hour layover on our way from Porto to the beaches at Nazare, which was JUST enough, but a full day would have been divine. Rick's suggested walk from the university down to town is a "must do."
Porto itself is wonderfully easy to navigate by foot (and I have bad feet), albeit hilly, and about as charming as it gets. Make sure to take the trolley or bus out to Matosinhos. If you get off near the end, it's an easy walk to Rua Heróis de França. While not ON the beach (weirdly none are there with views), it's parallel and a block or two inland, packed with restaurants, all of which are grilling your fish on hot coals. A local on the Portugal forum told us there really wasn't a bad one in the bunch! (We wound up at her mother's favorite, O Valentim, and it was indeed terrific.) Warning: The Arroz con Mariscos (rice and seafood) dishes, as well as the Cataplanas, which are seafood and vegetables cooked in special copper "space ships" in a tangy broth, are enough for a table of FOUR! (We found that to be the case at all our stops Porto/Matosinhos/Nazare/Lisbon.)
During your week in Lisbon, make sure to devote a full day to the sites in Belem, west of town, and also make sure to take the train to Sintra and devote a full day there as well. (Seussian is the best description for the magical palaces there!)
Enjoy!
Cynthia