You are absolutely correct with the left ear angle on the AP, it will not follow the line/angle of the trap, but the right ear does. (left and right as you are looking at the helmet)
I managed to get the height almost identical on mine and the 2 other AP kits I have built, but in saying that I had aligned them early on in the construction.
If you are not 100% confident that you can get the holes right, it is not worth risking the potential damage on something that is not CRL enforced.
I agree with Joseph that you can counter sink the lower screw more as it does appear to protrude quite a bit.
Great work on the build Mark.