RE: broadheads
I agree with the spin the arrow bit and reading up on the Easton Archery web site on proper tuning of your set up.
I use Muzzy Broad heads and have great field point and broad head placment. I do have to be very strict on my form when I shoot my broad heads, but they group just as well as my field points without adjusting my sites. Granted, I shoot a hard right-hand helical which helps stablize the arrow and I shoot a Muzzy Drop away to avoid any fletching contact.