If you saw the movie The Proposition, and understood it, please explain it to me?

So, I get that Ray Winstone can't find the main leader of this gang of outlaw brothers, so he tells Guy Pearce that if he can kill him, he'll pardon his brother Mikey, who is simple. But when does this supposed occur that everyone's in a snit about? Not at the beginning, I think, as it seems they are in some oriental house or something, and the lady's name who was d was like Eliza Watson or some such, which seems not oriental. And why, at the end did Guy Pearce kill his brother and the other guy, and who was that other guy, another brother? A nephew? And actually, why did that dude throw a spear through Guy Pearce, if he was with his brother's gang? Didn't he know who he was? I heard a lot of good stuff about this movie, but I was kind of disappointed. I prefer when people's motives are clear. That's why I didn't like 3:10 to Yuma. Alright, thanks.