It is a good idea to designate your broad head arrows. I have six set aside that have been spun and checked with each broad head that is mated to it. I use identical arrows for practice with the same weight field point. I use 100 grain field points and 100 grain 3-blade Muzzys.

I would say it is a bad idea to shorten your arrow, not only for spine reasons but also for FOC if you take too much off. This will mess with how level your arrow flies to the target. Once you get your arrows tuned and set up for field points, do not change anything to accomodate your broad head other than spin testing the arrow with the broad head and keeping the same broad head and arrow mates.

Also, if you are going to use a fixed blade, like Muzzy, try them out ahead of time at given ranges to make sure you have proper arrow flight before you get into the stand.