The thigh pack looks good, but trim more of the edge of the boxes. The knee plate...
I wouldn't trim anything off the thighs or cod until you strap more of the armor together. The thighs have a nice shape to them and shouldn't have to be trimmed unless you are really small.
I used a heat gun to make the butt plate line up with the cod piece. This will also help with the butt piece hitting the top of the thighs, between the legs.
The butt plate should just hang in place without too much tension on the crotch snap. I just clamped the rivet covers while the glue was drying, e6000 will give it some flex.
I used a similar paint+primer, the Valspar brand. I have never heard of this painting technique. From 2 feet away, I am surprised the coverage would be that good. Your helmet looks nice and shiny.