Most kids that throw curves also are over used, so the jury may still be out on that one.
Yeah you are gonna have lots of people come here and say I taught son how to throw a safe curve, or son's p coach taught him a safe way to throw a CB. Well, I don't buy it, even if safe, if you have success you are gonna be in the game more than other pitchers. Same way with a hard thrower that doesn't throw Cb's he's in the game more because he is dominate. You don't REALLY know, so you just eliminate what MAY be a problem until the pitcher gets older.
That's why young pitchers shouldn't be all wrapped up in pitching, a few innings a week, then play position.
JMO