Rating: 6 Not bad at all. You may want to try using Durham's water putty sprinkled over the structure that has been moistened with a flower mister (I use an old spice shaker for the water putty) it will give you a much finer, less lumpy appearance.
Rating: 8 While the tower itself could certainly resemble masonry more closely, the little details, such as the bales of straw, the firewood, and even the tuft of moss growing on the ledge, make this piece very natural feeling and homey, very pleasing. Good work!