My wife and I visited all of these stops last June, with the exception of Coimbra. We went to Sintra as a day trip from Lisbon by train, and found it very easy to do- I prefer that to a one night stand, especially with all the nighttime activity available in Lisbon. As was mentioned previously, Obidos can be seen in a few hours. It is possible as a break in the long drive from Evora to Coimbra- that is, assuming you are driving. As for Nazare, I would recommend it only if you want to spend time on the beach. Otherwise, it does not add anything to your experience that you won't be getting elsewhere. We spent two nights there as a base from which to visit Obidos, Batalha and the like. Also, we only booked a room in Nazare one day in advance, from Pinhao, once we knew the weather forecast was good. I think spending the first four days in Lisbon, and the last five in Pinhao and Porto will make for a great trip. In between, I'd suggest two two-night stops, selected from Evora, Coimbra and the Obidos/Nazare area.
