Plate tectonics started billions of years ago, so how exactly it got started is interesting but not relevant. I just had a conversation a week ago about whether plate tectonics was different in southern Africa a billion or so years ago; a long time ago a read a paper or 2 about whether there were large displacements across some of the African mobil belts.

You seemed rather reasonable admitting to Roger that your M6 quake periods were about the same as chance. Roger states that quakes are clustered, and many (most?) seismologists/earthquake geologists would agree. This is absolutely no problem for plate tectonics; it instead bears on stress. So, I don't understand your argument, and have not heard an explanation of flaws in plate tectonics from you that made sense.
Chris