Hi, Jax,
I would definitely recommend that you search through the forum and you will find a lot of opinions and reports from the Camino from Lisbon.
Just a couple of preliminaries -- have you seen the online guides published by the British Confraternity of St. James? There's one for Lisbon-Porto and one for Porto-Santiago (donation requested after you download them).
http://www.csj.org.uk/guides-online.htm
Also, by all means check the Via Lusitana's web page. They have a list of albergues,
http://www.vialusitana.org/caminho-portugues/albergues/ from Lisbon onward. There was just a note here yesterday about an albergue opening in Santarem, which you can easily find.
I have walked this way alone, and I enjoyed it very much. But you should definitely check out some of the not so rosy opinions, particularly Michal's. There is a lot of road walking, though the ViaLusitana is trying to move the path off the road whenever they can. The arrows are very good because the ViaLusitana keeps them in good shape.
I do speak some Portuguese and it was very helpful. Though many more Portuguese people speak English than their neighbors to the East, you'll be in a lot of remote little villages where knowing Spanish is likely to be a huge godsend.
I never stayed with the bombeiros, but was always able to find a relatively cheap pensao (pension) option.
Here are some notes from my Lisbon-Porto experience in 2009 (i was living in Lisbon at the time, so I did a lot of day trips out and back).
el-camino-portugues/topic5398.html
Things have changed a lot, there are in fact several albergues and a lot more traffic. But it is still definitely not a heavily traveled camino.
Here is a link to my pictures from Lisbon to Porto, in case you are interested:
https://plus.google.com/photos/10410577 ... p72psbzYFw
So, check out the threads on this forum, the search function works very well. and then let us know what questions you have, happy to try to answer.
Buen camino, Laurie
(And p.s., as you will see on the ViaLusitana's web page, they have a 24 hour a day SÔS phone with people speaking English, German, Spanish, etc. They will help pilgrims in many languages and at any time of day-- so make sure to bring the number with you!)