Temperament is heritable, meaning easygoing roosters usually sire easygoing sons, though nothing is 100%, since situations are different in each rooster's life.
NO rooster should ever attack the humans who feed and water the flock, even in defense of his hens. That's a stupid rooster. We keep only non-human aggressive (and more intelligent) roosters, like the big blue guy in my avatar. I've only ever heard of one of his sons being even slightly aggressive-he passes on his calm temperament to his progeny.
The trick is to start out with a rooster who simply never starts flogging people in the first place. If he does, cull him. Then, get another one, preferably from a line bred for good temperament. If that doesn't work, cull and try again. There are too many great roosters in the world to put up with a mean one. Life's too short.
Toddlers and small children do not belong around a rooster guarding hens-their movements are sudden, jerky and they are loud. Small kids can make roosters jumpy and touchy, even normally calm roosters. Kids screaming and yelling put my own sweet roosters on alert, even if the kids aren't on my property.