[NyteSky]

Hmm. The whole battle idea sounds pretty good to me, but maybe a little melodramatic. All depends on how you write it tho.
"After the first few chapters, dialouge will begin" This is a matter of personal preference of course, but it's usually best to throw something in to grab attention right at the start. Then you can introduce the needed information more slowly, throughout the story. Some very good authors have used this and I think it worked very well.
In what way are the characters based on your cousins? Do you go just with looks or personality or both or what? I'm doing the same thing in a book I'm writing with a few characters but I'm still not sure how far to go with it. Goodluck with the story, it sounds really interesting!