Wow! Thanks very much for all the thoughtful comments! (Poor Ichigo, bet "he" didn't expect all this debate about his nose. :P) It's definitely given me a lot to consider. I'm looking forward to getting better at OCF.
As far as cropping for the first photo goes - is this better?
Second shot seems like you're getting a little more ambient than you'd like. If you had shot with a faster shutter speed near your max sync, the back wall that's not lit would just be black. Unless you wanted some background? Your subjects would still be exposed properly by the flash.
Since the cosplayers are in all black, I wanted to make sure I had enough neutral background to set them off. I'll definitely keep the faster shutter time in mind for someone with more color!