Freebeard, that diagram makes me sleepy!
I did not start working on the shelves until the night before I left, too many other things were going on, but I had bought the materials.
I decided that, instead of coming up with something with all of the features that I desired, I would go ahead and make something useful now, and come back and spend more time and money later. Perfect is the enemy of good?
I cut the shelves, but need to trim them, cut the 2x2 that I bought for brackets, and install everything. However, I realized that my parents' room was the most cluttered in the house. They have two dressers, one of which is very large, two unusable desks, a couple of full bookcases, and every surface is covered, with a pile in front of everything, and they actually have stuff blocking the walkway. I really think that instead of building more shelves, it would be best to find a good Packrat Anonymous group!