Two challenges Anthony Doerr set for himself in All the Light We Cannot See

I've go to say: the exodus from Paris in advance of the Nazi occupation is a great extended scene in Anthony Doerr's All the Light We Cannot See - yes, it's a moment in history that we've seen before, notably recently in the unearthed Suite Francaise (blanked on the title for a moment) for example, but Doerr presents himself with a seemingly intractable challenge: telling the story from the point of view of a blind girl, so we get the exodus not as a set of visual scenes but largely as sounds, odor, interior perception. He carries on with the same tour de force when the girl, Marie, and her locksmith father arrive in the coastal town of Saint Malo, just in time for the Nazi occupation of that walled city. So far - about 25 percent through the novel - it remains a series of alteranting very short chapters, building up to Marie alone in the 6th floor of a building in Saint Malo during the allied air attack and an Austrian soldier, Werner, in the basement of a building under attack. The Werner chapters pose another challenge for Doerr: how to make a young man who becomes a Nazi soldier attractive and sympathetic. He does about as good a job as one could hope: we see how Werner and his sister, orphaned after their father died in a coal mine pushed beyond capacity to supply the war effort, live in terrible poverty; while his sister, secretly listening to French broadcasts, comes to understand the horrible truths about the Nazi party, Werner is recruited to a special training school and sees this - rightly - as his one chance to escape poverty and assignment at age 15 or so to work in the mines. He's not an ideologue - just a kid trying to make the best of things - but I am still kind of uneasy reading about the Nazi soldier as a good guy, at least so far. Yes, Doerr is willing to break with convention; he's a writer who's constantly trying new themes, new settings - perhaps to his disadvantage, as it's hard for critics and readers to see a persistent theme or style in his work. I would say his great strength is description and atmospherics, and his weakness is character: the two main characters in this novel, at least so far, are vehicles that carry the narrative and descriptive weight, but they don't feel like people, or even like "characters" in a novel in that they are very passive: things happen to them but they don't act, or even interact with others.