As far as the music goes, even if Armor Games allows it (which I doubt), you should still not use copyrighted music. I have a friend who was almost sued for using a copyrighted song in his work. Its better just not to mess around with it.
My suggestion is to go and check out the Newgrounds Audio Portal. There is a lot of awesome, original music there. And it is free to use! In fact, most developers on there would love it if you used their music. It is a really great resource, you should check it out!
