I always cut arrows the same as the draw length of the bow. Doing so will put the end if the shaft right at the front of the riser at full draw. This keeps the broadhead just in front of the riser. With the speeds today's bows are shooting, there's no need to cut them shorter.
Shoot them all. it is not uncommon to have one or two per dozen that dont fly as good
I've always herd that, but have never found it to be true.
Yep. I never get "flyers".