not sure of your specific question - but I can add that I miffed my application and here is what happened -
I actually checked somewhere that I am an illegal alien, or something similar - something so clearly out of whack with respect to the rest of my application that I got a call from a very nice woman who was processing my application and was looking for clarification. As it turns out, whatever mistake I made was common enough that they look for it. They sent me back my original application, I struck through my mistake, initial and dated the application and sent it back. I called back 4 days later, spoke to the same woman who said I was all good. Got my C&R a few weeks later.
My point is nothing too bad should happen if you miff one of the check boxes - as the BAFTE woman told me, these forms are complicated/misleading.
ETA: when the BAFTE called to check my application - they ended up leaving me a message at home. I did $hit marble for a day until I called them back and got a hold of someone. Generally, if you dont know what they are asking you for (like a nonimmigrant alien card) then you arent it/dont have it. Also, if you are very stuck - call the BAFTE BEFORE you submit your app - they will help you over the phone.