First of all, welcome to cruise-chat! I am glad you found us and also glad that our site was able to answer most of your questions.
I have been in both cabin categories you mentioned....we were in an ocean view balcony on the Freedom Of The Seas on it's inaugural voyage, and we were in a JS
suite on the Liberty this past June. We definitely preferred the JS
suite. Lots of room and a huge walk-in closet.
But the balcony cabin on the Freedom was nice, and it will do you fine for three adults for a week. The sofa bed has to be opened up to be a bed, unless the adult sleeping in it is 4 foot tall or less. As with most cruise ship "sofas", it is really the size of a love seat.
Suite passengers have their own check-in line, but beyond that I think priority boarding is by loyalty status with RCI. However, don't worry because they really keep the passengers moving and you will most likely be on the ship within 30 minutes of your arrival at the pier. It is an extremely efficient embarkation operation.