Isn't outside of the ballroom a balcony? My solution, high enough barriers and/ or invisible walls blocking you from jumping down. There could be a treasure chest or two there, as with the other balcony that Belle could reach towards the end. (You know, the cutscene just before the world's final showdown.)
I can understand the door leading into the forest, (It would add too much more content, plus you might have to consider the village in that case) but the one leading to a balcony (if I recall right) doesn't make as much sense. Maybe if they remake this for the Current-Gen, they could add the forest and village.. and include the villagers in the plotline, in order to make that world a little closer to movie's plotline.