I found Max's motive a bit confusing... did anyone else? I initially thought he went back to bartertown to get all of his *beep* back, but then he wants to save Master, and just ignores everything else? What did Master do for Max, and why was he so keen on saving him?
Also, why was the pig killer so determined to help Max out, I remember this being mentioned when they first met, but I can't remember.
I initially thought he went back to bartertown to get all of his *beep* back,
At the beginning of the movie, yes. Of course. Then he was exiled.
but then he wants to save Master, and just ignores everything else?
Master was an engineer. He was one of the founders of Bartertown. He knew all the secrets of the place. AT THAT POINT, Max and his gang wanted to survive. Escaping from Bartertown with some resources. It was a desperate move. It worked.
Also, why was the pig killer so determined to help Max out, I remember this being mentioned when they first met, but I can't remember.
Pig-Killer was just a fan. He admired Max. He "sensed" that Max was special. Just that.
Did they end up getting any resources though? I don't remember them getting any fuel, water, food etc, just grabbing Master and leaving.
Life is unpredictable. They ended up destroying Underworld, damaging Bartertown and escaping aboard the "Junk Train". There was no plan. Master was instrumental because he knew how to make the Junk Train work, to begin with.