The prologue is pretty good. It gives you a bit of mystery to keep you reading.
Chapter one seems a bit better now, being told strictly from Mateo's view, too.
I'll agree with Asmodemon (man, your name is going to get typed Asmodean so much on here...) on the assessment of chapter 2. The problem as I see it is that you're not going to be reminiscing much when you're freaking out about seeing a murder. You're going to be adrenaline-pumped (fight or flight mode). So you're going to be focusing on the here and now, not three months ago. Personally, I would consider moving the flashbacks until he's in a more calm environment, like his room. You want to keep the tension ramped on his "getaway", and then slowly cool off as he gets home and he realizes he's in the clear. It's a bit bumpy right now, with tension, flashback, then more tension.
There is some info-dumping about the organization, too, but you definitely have to watch how you say things. If the person wouldn't say it naturally, then don't force them into a verbal info-dump. Regarding Asmodemon's comment about this, you'd probably have to go with something like "Look Matt, we've been around for centuries. We've got you covered." or something. Show the experience, but in the natural tone (which from most of your book, seems to be a fairly light, almost comical one).
Chapter 3 I didn't like so much. The only thing you do is introduce Agathan and set up what your chapter 4 is going to be about (the final meeting). I think a part of it is because I was instantly suspicious that this wasn't Benedict giving the message, because of the way he freaked out about it. Also, why wouldn't Benedict just call him? For that matter, why wouldn't any of them? I'd imagine a phone call is a little easier than making scrolls appear out of thin air.
I don't know. It just doesn't have much happening compared to your other chapters.
Chapter 4: hrm. Well, I know you need to start dropping information, but again, I think Asmodemon has it right that you need to make it a little more natural. Ben's a bit too verbose in his descriptions, which makes it feel like you're just doing it for the sake of the reader, even if Matt has the same questions. Honestly, I would have expected some of these questions to be answered by now, if he's been doing this all summer (not that all of his jobs would be this involved, but still). You also have some fairly large paragraphs in this chapter, which I would avoid (half a page is pretty big even for an adult novel).
Okay, so here are some difficult situations for you, since I'm one to find faults with systems in general.
First: How can Mateo hit Barry with a trash can with enough force to knock him over? I would think this would violate his restrictions on his powers, personally. Especially given a head shot, that's likely to cause some permanent damage, even without a slit throat afterward. I'm not sure whether the Guardian Angels have to follow the rules a little more strictly or not, but I would make them. Bludgeoning someone isn't very nice.
Second: There is an innate problem with the scenario. By hitting Barry, you are restricting his ability to carry out his free will. Any time two people are a part of the equation, if their wills differ, you're going to be stopping one to help the other. I'm not at all sure how you want to deal with this, or explain it away, but this could become a very big problem throughout a whole book. It's more than a little hypocritical to say that you can't interfere with Sheila killing Barry when you presented the opportunity by knocking him half-unconscious and preventing him from escaping. Barry *could* have chosen to let her go, too, but once he was on the ground that choice was completely removed. Fun, eh?
Third: Can an Angel use telekinesis on a person? They aren't particularly heavy objects in comparison, so why not just freeze them in place? This still removes their free will for the time, but it's a lot nicer than a can to the head. Or, why not just move them away? Let Sheila get out of the alley and be long gone before letting him go. Ben says you can't use mind-control, but telekinesis certainly has no restrictions on body control.
Fourth: Okay, so telekinesis is a very versatile power. What would be their "second level" powers? Honestly, there are very few situations I could think of that I wouldn't be able to solve with TK alone. Car crash? Stop one of the cars. Building falling on someone? Move them out of the way or push falling debris away from their position. Nuclear missile attack? Deflect it. See where I'm going? They already have more than enough power, so what's the power ladder look like?
Hopefully these situations/questions give you some things to think about moving forward.
