I don't think he would say he was being framed as #3 suggests. I rather think he would excuse burning barns through focusing on the perceived slights that he received from those higher up above him in the social class system of his context. His crimes, according to him, would be justified through the terrible and shocking way that he has been treated.
To change the point of view of a story, ask yourself what kind of person that character is. Abner Snopes is a cruel, brutal man who bullies people for the fun of it. He enjoys inflicting pain on others, both physically and mentally. So ask yourself how Abner would tell this story. What would be his reasoning for setting the fires? Perhaps Abner might tell us of his childhood, giving us some clue as to how he became such a horrific man. Was he himself abused? Why does he hate the people who hire him? How does Abner feel when Sarty betrays him to Major de Spain and runs off?
Basically, the story would be very different because it would take on a different mood. Abner is bitter and hateful, and as the narrator, his story would reflect these emotions. The author would have to get in the mind of a man who seems to have no conscience, who enjoys inflicting pain on others, and loves to destroy property through fire.
The story would be as if the world is out to get Abner, everyone is against him, and I am curious who he would blame for all the barns burning. I think he would say that he was being framed, and it was a terrible coincidence.