This is cool and I'm glad it works for you, but it doesn't really seem desirable to structure every single minute of your time in this way.

I agree: as I note in a recent comment, for maximum productivity one should allow oneself some predefined amount of leisure time. And I don't think it's advisable to lump these periods into the "unstructured procrastination" category: procrastination, however unstructured, is accompanied by guilt and other unpleasant feelings, whereas predefined leisure time should be enjoyed with peace of mind, in the knowledge that one is doing what will actually make one more productive overall. (I'm using 'productive' in the broader sense of 'conducive to the fulfillment of one's long-term goals', whatever these goals may be--being happy, saving the world, earning more money, or what have you.)