failure is probably due to a pivot tear. hard to say what would cause it, but it obviously happens enough to warrant checking the issue. I though for sure with the added strain on the bushings at my ride height that my bushings would be shot by now too. But they are doing fine for now.
The rear disk kit is in "order" it just requires some clearance to be made.. Where the spindle mount on the axle comes back around. Aside from that, you need mk4 calipers, then i suggest going with adjustable valves, and I am still working out the E brake.