That is nice!
I would advise you to avoid the following points though:
1. Rota dos Miradouros
2. Miradouro de São Silvestre
9. Miradouro de Casal de Loivos (which access is a bit too aggressive as far as I remember)
15. Miradouro de Santa Bárbara, because you will pass by it, en route on your 6th day.
I can add at least two points that I think are worth a visit. I will send you a file of what I can recommend based on that. And the ou can overlay the two files and work with it as you like.
Armadillo is in The Douro Valley and waiting for you.