Bob, looks excellent...

How hard is it to remove the broadheads from the target? Does removing them cause damage to the insulation, or do they just back out of the same slits/hole they previously cut?

Minus the insulation, I have 95% of that laying out in my garage. The insulation only cost you $20? How many 4'x8' sheets did you need to buy? How thick are the insulation sheets? How did you cut them?