See these posts on travel between the Algarve and Lisbon on my blog here:
http://bit.ly/9F2sFc
3: There is always the option of one of the two bus services Renex and Rede Expressos. These leave from closer to Albufeira than the train, the station being 8km out.
In summary, finding your way into Central Lisbon is not for first timers, and finding parking is becoming more and more difficult. You will end up stressed. There are enough good public transport links between Albufeira and Lisbon to make a day trip doable using this means.
