I'm very much a fan of the CTR and a 16" LW barrel. I think the 14.5" looks better and will make almost no difference in accuracy especially since you're using the Aimpoint micro (excellent choice BTW). But I don't like the idea of pinning on the muzzle device just to shave off 1.3-1.5" and I think the extra length is beneficial with the midlength gas system.
Sounds like you're well on the way with BCM, can't argue with your choices in any way.
CTR/BCM receiver extension/buffer and Daniel Defense 16" CHF LW midlength below: (that extra 1.5" in front of the FSB does make the barrel look long)