Alright, I now have another Skype "chat"/interview request thanks to that email. After fumbling through the first one, hopefully I do not screw up this one. I was so nervous and unprepared when they asked me if I have any questions for the program. My mind went totally blank at that moment.
I do wonder about contacting ad com and submitting new material after the deadline. I think by now it is too late to do anything, but I kept wondering if I should've sent in my better writing sample...