Just stayed in cabin 7576 - which would be 4 doors down from the one you mentioned. That cabin is definately closer to laundry, but I don't think it will be a problem. We had no problem with crowded or loud hallways. The only night I noticed a crowd in the laundry (2 other people besides myself) was on the formal night when we needed the iron.
I wouldn't worry about the dryers heating the room either. The laundry is across the hallway and each cabin has its own temperature controls.
We had gorgeous weather for most of the trip. Florida was freezing when got there so that was a letdown. The weather at ST. Maarten was in the 90's & St. Thomas was in the 80's. Both days were sunny. Castaway Cay was picture perfect - hardly a cloud to be found & nice & warm. We had one day at sea that was pretty cloudy & another day that sprinkled here & there.