I'm not entirely sure about the specific 'oro plata mata' story. It could be something specific to a certain region, culture or even a local folktale. Without more context, it's difficult to provide a detailed account.
Delectable negro fiction can be described as literary works that captivate readers through their portrayal of black characters and their stories. It might incorporate elements of history, identity, and community to create an enjoyable reading experience for a wide audience.
In historical fiction, the use of 'negro' can be a complex matter. Historically, it was a term in use, and in some cases, it might be necessary to use it to create an authentic portrayal of a particular time and place. For example, if you're writing about the civil rights movement or earlier periods in American history. But when using it, the author must handle it with great care. It should not be used casually or without respect for the history and the feelings of the African - American community. It could be appropriate if used to show the language of the oppressors in a historical narrative that aims to also highlight the struggle against discrimination, but again, extreme caution is required.
It depends. In some cases, if used within an accurate historical context and with proper sensitivity, it might be appropriate. But it's a very sensitive matter and needs to be handled carefully.
I'm not sure. It depends on the author's inspiration and intentions. Maybe you could look for author interviews or related background information to find out.