I nicked the tip of the taper on a bottom bracket spindle. Is it still safe? I had to cut the crank arms off of a bike I'm working on. Used an angle grinder. Despite my efforts to avoid damaging the bottom bracket spindle, I nicked it in three places, all at the tip. 

The bearings and surfaces are all dandy. Is it safe to use this with new crank arms?

  This is the worst of the three.
I'd reuse that spindle. The tips bear the smallest load. A nick near the center of the spindle would be more significant