If you are staying at the YC, almost all rooms have a full balcony; only a few do not.
If you are staying at the BC, only about half of the rooms have a full balcony, with most of the rest having a standing balcony.
I can’t really think of a bad water view room, though some could be noisy, if overlooking Stormalong Bay. There are not nearly as many king bed rooms, as there are two queen bed rooms.
All of that being said, you can place a few room requests, ahead of time, with, of course no guarantees. Prioritize your requests in order of importance.
When you arrive, you can ask the CM at the front desk you tp over the info of the room assigned. If you are completely dissatisfied, you can politely request a different room, if any others are available.
Keep in mind that during busy season, such as Spring Break, they may be at full capacity.