wow! Thank you very much for the detailed critique! That's exactly what I was looking for!
I will keep this things in mind for next time. I was mostly focusing on trying to the get lighting right with the flashes, and not so much on the subjects. Quite a few of the shots ended up having bad composition, just because I was so concerned with the flashes and ended up paying little attention to the composition.
Thanks again, your comments throughout have been a great help!