well ok, here goes,, hmmmmm
well 68 or 66 would have been long enough,, if you weighed the mass of the bow, I bet its over what you need for that draw weight and draw lenghth,,
so for example if you did cut off 6 inches and weighed those 6 inches of wood you would see thats quite a bit of extra weight you got going,,on the tips,,
options,,
1 shoot a heaver arrow and see if it is reasonable feeling like that,,
2 make the outers work as suggested,, so you have less limb working,, or it would shoot like a shorter bow,,( you would miss your weight)
3 cut the bow shorter and retiller
your main problem I think is it is just slighty overbuilt,, try the heavy arrow first,,
also if the cast is a consideration,, shoot with a chrono,,, if the cast is great, ,leave it and put a thick leather handle and deal with the shock,,
if the bow is slow, ,it is telling you it is a bit overbuilt,, shorten and retiller,,
