Yes, Chris is portrayed as a good guy in American Woman.
Chris, played by Aaron Paul, is introduced into Deb's life as she navigates personal growth and new opportunities. He is explicitly described as a decent boyfriend, indicating a positive and supportive presence. His commitment to Deb is further highlighted when he marries her. Beyond his relationship with Deb, Chris also steps into a crucial role for Jesse, Deb's son, becoming a father figure. This significant responsibility and his acceptance of it underscore his caring and reliable nature, firmly establishing him as a positive force within the film's narrative.
Chris's actions and character traits, as presented, consistently align with the qualities of a supportive and responsible individual.