Totally agree with @styles27 HC rooms are HUGE, as are the balconies. You take that and the other is for the family with the teens.
But to answer your first question, no, you had the option to review the cabin choices at the time of booking with your TA. If you didn't understand the deck plan you could have asked for assistance at that time. In fact, he/she probably shouldn't have booked a HC cabin that far out as it technically should have been for HC use only. (These cabins do open up for general sailing about 60 days out if not already booked)