From the anecdotal evidence I've seen on IMS failure, it seems to be luck-of-the-draw more than anything else. I don't think there's much one can do to prevent it.
That being said, why are you so worried about it? Sure, it can fail, but every car seems to have a component that is prone to catastrophic failure. You want something really scary? The e36 BMWs (3 series from 92-98) had incredibly weak mounts where the rear subframe bolts to the unibody. They often ripped loose, dislodging the entire rear subframe. It was about as expensive as IMS failure, if I recall, but a lot more messy. And yet I drove one for years.
Enjoy your car. If it happens, it happens. Hopefully it won't.
