I always figure a bowyers recommendation is just that. A recommendation. It' s not the final word.

You have to play with nock location, brace height and arrow spine until you find the right combination for you. Field points will let you get away with a lot, but broadheads are always the truthsayers about how you' ve got the bow tuned.
I' d try dropping the nock point to 9/16 and see if it cures the arrow kick. Keep lowering it until it does clear up.
65-70 spine arrows, 28.5" long at 51 pounds seems a little stout to me, but if they' re shooting good they' re fine.