Furies of Calderon

It's probably just me, my interpretation of how the secret agent would act, but there are two scenes near the end of the book where she sat idly on the sidelines while an important fight took place and I just could not believe that she would do that. It felt wrong, and kind of ruined the little enjoyment I was having.

My other main issue is possibly due to listening to the story, rather than reading it. Basically I don't understand the ground rules of the world. Tavi is unique because he has no furies. But that means that the Knights, the Legionaries, and Cursors all have furies. So... what's the difference? The Knights Aeris (spelling guess?) can fly around but the others cannot? Maybe? The Legionaries act like none of them are able to call the furies. But that would make Tavi no longer unique. I just don't understand the rules here. And that confusion was annoying, which made me simply annoyed with the story.

I'm disappointed because I quite enjoy the Dresden Files, and this is no Dresden Files.