#1, This looks like a crack that came from the combo of a weak cover/dull drill bit. In my experience, its the heat caused from the dull drill bit, not the vibrations, that causes the cover to weaken, hence become more susceptible to cracking. Either way, the guy was right about dull bits causing alot of this.
#2, I've replaced many balls, especially if they're that new, that have cracked out even though they have finger inserts. That is generally a cop-out the ball company's take, but rarely have I seen them be a stickler on that. So long as your bridge is 1/4 of an inch, and the pin isnt drilled into/out, it should'nt be a problem to get a ball replaced, and the ball companies are generally cool about it. I mean, 9 games, there's no way they wont warranty that. :0