Ok, I've written a huge critic thing here, in which i carefully chose my words, but it just got deleted, so I'll cut it short:
I don't think your reading is anywhere near your writing and it might discourage potential fans to pay more interest.
You do have a likable voice, nice audio quality and it's a plus that you show yourself while reading out loud.
But there are some things that you could improve:
-You are not using your breath efficently -> You could use your diaphragm more. You could get into a more natural position ( Imagine a string is attached to the middle of your head with a helium baloon on the other end, that straightens your spine and shoulders back a bit; if you aren't doing that already -> legs 90°, feet 90° and sit on the edge of your chair)
-You are not conveying the ideas you are reading out loud all the time (this goes especially for your "narrator voice") -> Think of reading this out loud to a real person / Have concret images of what you say, "fighting them would be better, than suffocating in the smoke" should do something with your voice. If you'd be in that situation you'd reflect that in your voice. Even if you were the narrator, it should have an "explaining tone" to it at that moment.
-You are talking without having a goal in mind -> know what you are reading, think of what the text does at that moment, and read towards a goal. For example: If you have an explaining passage, know that it is there. Read it from the beginning to end with that in mind
-You have some power slummering in your voice, use it -> It feels like you are holding yourself back a lot. Try to not do that ;P
-You are rushing -> Don't rush. (To be fair, rushing is the most common problem I can think of right now. And its super hard not to rush and still stay natural)
-It feels like you think "that was silly" after "getting in character" at times -> Believe in yourself! ;p
Don't think you are doing everything wrong. Those are small things, but your book seems to be on a professional level, so you probably want to show it in the most favourable light possible.
Also if you still have questions or if you want to talk about those things in detail, we could do this in skype/email/whatever in german. I'd be able to explain what I mean better then. :x
Hm.. I'm interested: In what languages will you release the book?
*cough* "Cut it short" :D TL;DR: Super cool that you've written a book, it seems to have a high quality, but I don't thinkyour reading is up to it.