"Black Burton" is what now we say a modern day bully. Burton was already busy "picking a quarrel" with a "tenderfoot" in the saloon, and Thornton decided to come to the aid of the newcomer. Burton then took out his frustration on Thornton, hitting him without notice and nearly knocking Thornton to the floor.
I would say B, the narrators inner thoughts and feelings.
Number 3 is SWAN... I believe. The rest is all correct
Unos son pequeños........
Rising action is the answer