I skimmed the first few pages and only one thing came to mind: is English your first language?
You really notice it in your dialogue. I reccomend really listening to how people talk...because that is definitely not how we talk. You can also try reading the dialogue out loud, which is what I do. I think you'll agree that it sounds way off.
I'd love to go through and point out the little things, but I think you should be focusing on the big issue right now -- and that is your dialogue.
I'm not trying to be mean or anything like that, I'm just trying to help you become a better writer by pointing out your flaws. Hope this helps.