DislikedDave,
why don`t you count the wave "v" of the SPX pattern which started at 6th of march as an "Ending Diagonal"?
Actually wave "c" of "1" (ED) is unfolding.
SixerIgnored
However, regarding your first part, the move off the March 6th lows cannot be an ending diagonal as the sub-waves are unfolding 5 not 3 and there is no overlap between the waves. Additionally the overall structure is not taking on a wedge shape with converging trend-lines.