I commend your efforts of writing a screenplay, but this story is way too random. There is no identity to this town. It took me 10 pages of reading before I even realized that this was supposed to be set in the wild west. That shouldn't be. There is too much dialogue, and a lot of the dialogue would not correspond with how they talked back in the 1800's. There is no background on the saloon scene with the man who was suddenly killed and Dirty Dan should have been portrayed before hand either robbing someone or on a wanted poster or something so the audience knows he's that vicious. The plot on the story is also suspect.
Sorry, this is just my brutally honest opinion. I hope that I am wrong and you sell this screenplay and make millions of dollars. Best of luck with everything.