I'm appaled at the thought of having to descend even one level to get my breakfast, and I'm not exactly royalty. I extrapolated from that
Another thing to consider with the walls: will people standing on the battlements on top of a 10 level tower (300ft. above the ground, you say) be able to accurately hit an attacker with any weapon in their possession? Otherwise, I'd say it's a waste to deploy troops there in the event of a ground attack. Of course, if there's a danger of aerial attacks, sure, go ahead.
Or maybe make the courtyard wall lower, the front towers lower as well, and add side-mounted towers (towers that don't go all the way to the ground) to the main building on the higher levels?