They are hit and miss, you'll have to be the judge of that. I personally have never had a nice rooster with hens but my spouse who wouldn't blink an eye at kicking a field goal with one never had problem with the same roosters I had issues with. Show your dominance and there are some helpful...
Roosters really can't save your hens from predators other than getting eaten first when it comes to foxes, raccoons, coyotes etc....But defiantly pen him up away from the children because they are dangerous to tender eyes and faces and not worth the risk.