Perhaps you've looked at this, but I'd recommend that you look at the top shock bushing(s).
I has similar rattles in my 260E rear suspension, due to worn busings in the thrust rods. (may not be the proper name) It was metal to metal, but on the inboard side, so I could not clearly see it.
I also got quite a yaw during WOT due to geometry changes during thrust. New rods, no rattles or yaw.