Most likely, Sam and Dean Winchester would be main characters. They are the central figures in the Supernatural series, and any fanfiction set in that universe would probably revolve around them. They are the ones who usually deal with the chaos and the supernatural threats.
In this type of fanfiction, the character development can be really fascinating. Since it's not bound by the show's exact plotline, the author can take a character like Castiel and develop him in unexpected ways. He could face moral dilemmas that are more extreme or form alliances that we wouldn't see in the original show. This allows for a deeper exploration of the characters' personalities and what makes them tick.
In such fanfiction, there could be chaos and intense battles among heroes and villains. The plot might thicken with unexpected alliances and power struggles.
Basically, a loose plot in a novel means that the storyline lacks cohesion. The events and developments might not build upon each other smoothly, and it could be hard for the reader to follow a coherent narrative thread. Maybe there are too many subplots that don't contribute to the main story or characters' arcs.
In the 'the gingerbread man loose in the school story', if the gingerbread man is loose in the school, it would be a very interesting situation. He could interact with different elements in the school. Maybe he would visit the library and start reading the picture books, or he could go to the art room and get paint all over himself. His presence would likely make the school a much more exciting and unpredictable place for both students and teachers. Teachers might have a hard time getting the students to focus on their studies as they would be more interested in the gingerbread man's antics.
One common loose end is a character's motivation. If a character does something important in the story but their reasons for doing it are unclear, that's a loose end. Incomplete story arcs are also frequent. For example, a character starts on a journey of self - discovery but the journey seems to end abruptly without any real conclusion. Additionally, any sub - plots that are dropped without resolution can be considered loose ends. For example, a side character's mini - adventure that just stops without any sort of wrap - up.
A "loose ends novel" often leaves some plotlines unresolved. It gives a sense of realism as in real life, not everything is neatly tied up. For example, a character's backstory might be only partially told.
I don't know what kind of novel Rogue Saint is, because I'm just a person who likes reading novels, and I don't have any specific context information to provide. If you can provide more information, I can try to answer your question.