The sway bar link is mounted to the lower control arm, right next to the shock. It looks like the loading of the sway bar/sway bar link that occurs when lowering is taking load off(or compressing) the shocks and putting it straight to the body via the sway bar. So the shocks don't appear to be able to use the full travel and absorb those bumps and dips. At least that is what it looks like to me.

When you lower the car the lower control arm moves up. This is what exaggerates the negative camber in back. It also pushes the fixed length sway bar link up, which pushes the sway bay up just like you were cornering. Only it is seeing that load ALL the time, on both sides. Since the sway bar is mounted directly to the chassis, those bumps get transmitted directly to the chassis as well. Could this be part of the reason some of the sway bar mounts are breaking????