Die cracks in 2006 P Kennedy's

gemstatecoins

I've been going through a bag of 2006 halves and have come across about 10 coins that have die cracks on reverse at 6 o'clock, some more pronounced than others, even a few have small die crack starting on obverse at bottom left of Kennedy's neck in addition th the one on the reverse. How common is this??? Oh, and also I did a bone head thing... I picked up a group of six coins before putting on a glove the 1st time and the best coin I have come across now has fingerprints , Is there a safe and easy way to remove these?? I don't want to scratch coin... They are only on the reverse.