To spin-test broadheads, I use a magnet stuck to the overhead ductwork in my basement. Wobble is pretty obvious, and it's easier and safer than trying to balance it in your hand.

I also leave my broadheads alone once installed, alinged, and spun.
My hunting arrows get tested with field points after assembly, and then they are re-tipped and put in the quiver until called on by a deer.
A tip only comes off if dammaged.