I like how the castle seems to sit within the rock landscape rather than just on it. The curved walls are awesome and I think I like the angled-ness of the buildings the best. I also like the balconies and the windows seem appropriate and not over done. Props on the gate house and breaking up the BGW syndrome.
It really is perfect as is. The only think I might be tempted to add/change if it were mine, would be to add more flags, maybe try tiled water, and possibly switch out some of the 1x2's with some of the modified 1x2's to add texture or for adding leaf pieces.