What is the meaning of the Hadith: "No believing man should hate a believing woman; if he dislikes one of her characteristics, he will be pleased with another"? And what is the difference between custom and disposition?

The meaning of "does not dislike" is "does not hate." A believer does not completely hate a believing woman; if he dislikes one of her traits, he will be pleased with another. "Trait" (al-khuluq) refers to a habit a person acquires.