I don't know how much of behaviors is hereditary and how much is environment. I suspect a bit of both. So my rule is simple, If they (hens or roosters) exhibit behaviors detrimental to the flock or me, they don't breed. They generally don't hang around long either.
There are pros and cons...
What are your goals for that cockerel? Why do you want a rooster? The only reason you need a rooster is if you want fertile eggs. Everything else is personal choice. Personal choice can be a strong drive, but that is a choice, not a need.
I don't know how much of this is an age thing. I...