According to narratology, the story is the narrative structure that can actually remain constant all throughout the history of literature and storytelling (Gordon, "Narratology"). The difference between plot and story is that plot refers to the different events that make up the story. The plot is the main elements of the story and can be diagrammed in terms of structure and development. Story, on the other hand, refers to the main idea or the general theme revealed in the plot. The same story can be and actually is told over and over again. What makes a book or other storyline different from another is the elements of plot that are used to develop the story.
Since a story is a basic theme or structure that can actually remain constant I would actually hesitate to say that it has any requirements that need to be fulfilled. In its raw essentials, Jane Austen's story in Pride and Prejudice is a story of girl meets boy, which is of course the classic structure for any romance. However, Austen adds many plot elements to also make it a story about self-discovery as well as about reckless behavior. Through Austen's plot techniques, both Darcy and Elizabeth realize their own character flaws and amend them. In addition, Wickham's behavior towards both Miss Darcy and Lydia help Darcy and Elizabeth realize the extent of their character failings. Both Elizabeth and Darcy equally feel that their pride prevented them from exposing Wickham's true nature, which would have prevented any danger. We observe this on Elizabeth's part when, after reading Jane's letter, she says to Darcy, "When I consider ... that I might have prevented it!--I who knew what he was. Had I but explained some part of it ... this could not have happened" (Vol. 3, Ch. 46). Likewise, we learn in Mrs. Gardiner's letter to Elizabeth explaining Darcy's involvement with seeing to Wickham and Lydia's marriage that Darcy believed it was "owing to himself that Wickham's worthlessness had not been so well known as to make it impossible for any young woman of character to love or confide in him" (Vol. 3, Ch. 52). Hence, Wickham further complicates the plot by being one primary source through which both Darcy and Elizabeth reach their self-revelations, as well as the source the storyline's greatest conflict reaches its climax, creating a story about reckless behavior as well as about love.
Hence, we see that Austen's story does not lack anything nor does her plot fail to develop the story.