The provided information for 'On Swift Horses' details the film's focus on queer relationships, including gay men and a lesbian character, and themes of identity and self-discovery within the LGBTQ+ context of the 1950s. However, it does not provide any specific details or mention of transsexual characters or themes.

The movie does not contain any action or adventure elements.

The film is an adaptation of a novel, and all main characters are portrayed with consistent gender identities as established in the source material and historical context. No sources indicate any gender changes from the novel to the film.

The film's major characters, including Muriel, Lee, Julius, Henry, and Sandra, are cast with actors whose ethnicity and appearance align with their established or implied racial backgrounds in the source material and historical setting. No character canonically established as one race is portrayed as a different race.