RE: Help with F.O.C
I can't help with the weight of your arrows. I will say the FOC on them is probably in the 10-12% range (might be higher), given 100 gr broadheads with feathers on a 28.5" arrow. FOC is the percentage of weight forward of the center of the arrow. With broadheads, 10% is generally considered the minimum. You should be fine with your setup.