Congrats, Blake! It is indeed a great route and an awesome achievement!
I walked last year and fell in love with Portugal.
These are very good tips indeed
I totally second number 4 and 5 - I wore very cushioned trail runners to help avoid the impact of cobblestones. Another tips as well:
1) If you go to restaurantes in Portugal, politely refuse all the "extras" they start bringing to the table (such as bread, olives, dips, etc). They are not included in the dishes price and you may end up with a much higher bill than expected. "Nao precisa, obrigado" (pronounced 'Noun Prey-ceesa, obreegadow") means "no need, thanks".
2) After you cross the bridge from Portugal to reach Spain, remember they do the siesta on most Spanish cities. EVERYTHING closes from 2pm to 5pm. Then they re-open until late.
3) Food is brilliant, even on the cheap Menu del Dia options. Try Port wine and Francesinha (a croque monsieur on steroids) in Porto and Pimientos de Padrón (peppers) in Caldas de Reis or Padrón. Also try Pastel de Nata, available everywhere in Portugal. I tried the latter about 25 times while I walked, as I wanted to be really sure about liking it. I think i do, but I may try again to be sure