I like my astro-turf idea better.
I know what you're talking about with the aggregate. Too bad there isn't an epoxy tough enough to stand up to TX heat. There is a company in OH (maybe other states, too) called Nature Stone that uses a thick epoxy to seal the stone floor/driveway/etc. From the looks of it, though, it's still not a smooth surface. Probably a lot nicer to walk on barefoot, though, than just stones tarred to the driveway.
The problem here is not the heat, it is the black clay ground we live on. Think of it as the opposite of frost heave up North. The black clay shrinks in hot, dry conditions, and what's on top collapses. Driveways and sidewalks are least able to take it. And, aggregate driveways and patios are worse, because they are not as strong.
The saying here is, there are two kinds of houses in North Texas, those with foundation problems, and those that will have foundation problems. My foundation is 16-inches thick, and I had to have the front of my house jacked up and piers installed that went down 16-feet to bed-rock. Driveways, patios and sidewalks are four-inches thick. In August, my driveway is typically three-inches lower than in January. Not all of the sections move the same amount. It gets really interesting during a long drought.
CD