Washer welded to pin wouldn't be a bad idea, but I doubt these will EVER fall apart. I've been a mechanic since the early 90s and have never seen a failed split pin in good condition. As far as adding load to these bushes, I can't really see why they'd need it. They're not weight bearing and when you're on the road, presuming you're not trying to do massive scando flicks into corners, the swaybar bushes really wouldn't be getting loaded or even moved that much.

