Firearms don't "go off" unless you pull the trigger. They also don't "go off" if you drop them; Federal standards and rigorous testing to the same ensure that.
As long as you practice appropriate trigger discipline [0], your firearm is no more dangerous than a club.
Quite. And one can always count on nervous 19-year-olds to practice appropriate trigger discipline.
As for dropping them, the .45 pistol the military still used 30 years ago, could do that. But no doubt they are all off the street, or at least the discriminating felon won't carry them.
As long as you practice appropriate trigger discipline [0], your firearm is no more dangerous than a club.
[0] As our buddy Vincent here is not: http://www.imfdb.org/images/2/28/Pulp-1911c.jpg