Melanie McGuire is the central figure in this story. She was likely involved in some sort of criminal case that led to her being associated with the 'Suitcase Killer' moniker.
In the absence of further details regarding 'Mr Bates the Real Story', Mr Bates could be any number of things. He might be a character from a specific place or time period. It could be that he was involved in a historical event, and this 'real story' is about uncovering the truth about him. He could have been an artist, a scientist, or just an ordinary person with an extraordinary story that someone has decided to document as 'Mr Bates the Real Story'.
Yes, she might be. There are many creative people like Melanie Hamrick who are often involved in various artistic pursuits, and writing a novel could be one of them.
Well, without having read the 'melanie and everett novel' it's hard to say exactly. They might be characters with a complex relationship, perhaps lovers or friends. Maybe Melanie is a strong - willed female character and Everett is her counterpart, with different personalities that create interesting dynamics within the story.
Without more information, it's hard to say exactly who Mr Bates was. He could have been an employee at the post office, like a postal worker or a manager.
Since we don't know the details of the story, Melanie could be anyone. She might be a young girl who has a passion for pizza and the story could revolve around her adventures in finding the best pizza in town.