Not necessarily. Nell could be a completely made-up story or have only a loose connection to reality. It all depends on the author's imagination and the creative process.
Most likely not. Usually, such works are imaginative and not tied to actual happenings. The plot and characters are crafted from the author's creativity.
Well, from the title 'Renegade Angels Novel', it seems likely that the story focuses on angels who are rebels in some way. It may tell the story of how these angels come to be renegade. It could be due to a difference in ideology, like they might have a more compassionate view towards humans than the traditional angelic view allows. Their renegade actions could then set off a chain of events that include battles, both physical and ideological, with other angels who abide by the old ways. And as the story progresses, we might see these renegade angels either succeed in their mission or face a tragic end.
Well, in the 'Renegade Star Novel', it may tell a story of a lone wolf type of character. This character might be a pilot or an explorer. The story could revolve around his or her personal growth while facing various obstacles in space. There might be elements of mystery, like ancient alien artifacts that hold the key to something important, and the protagonist has to figure out what to do with them.