4 and 5 are my faves. I saw the dude in the shadows in #4 AND THOUGHT ,"That guy looks familiar...where do I know him fr--'DOAH! It's da OP!!!"
Good balance for the most part, but I think moving the flash around to a bit more frontal lighting position would have helped. OR....slowing the shutter down a bit to get more fill on the faces. Then again, I do not mind, in fact I almost like, the slightly hot rim-lighting, and the foreground/background balance looks nice. I think you could probably add digital fill light and make these almost perfect. For a first try, these look very good!!! your artistry is pretty high!