I'm not certain who Larry Novak is without more context. He could be the author who created this original Christmas story, or perhaps a character within the story itself.
Yes, there are. You can find some great Ali Hazelwood books fanfiction on platforms like Archive of Our Own. There are many talented writers who create interesting stories inspired by her works, often exploring different relationships or scenarios that were not fully developed in the original books.
I'm not sure if there was a character named Larry Novak in 'A Christmas Story'. I don't recall such a name from the movie. It could be a relatively minor character or perhaps not in the movie at all.
Well, her fiction books might have vivid descriptions. For example, if it's a story set in a small town, she could describe the cobblestone streets, the old - fashioned shops, and the friendly neighbors in great detail.