It's literally a roll of the dice, on what kind of roo you are going to end up with. He may be the nicest, treating the hens good, and respecting you and your family. Or, he may turn into a total brute, abusing the hens, and attacking you or anybody else that gets into HIS area.
There is nothing you can really do now, that will affect his future behaviour.
Now, as far as what you can do when he gets older. Don't let him mount or mate hens in your presence, knock him off and make him back away. YOU are supposed to be the dominant one, not him. So don't let him show dominance by mating the hens in front of you. If he challenges you, walk him back. Just keep forcing him back by walking right at him, and keep going at him, until he turns away. Only then, have you won the dominance game. Or you can pin him to the ground, then pick him up like a football, with him looking to the rear as you walk him around fro a bit. This will have to be repeated over and over, as some roos are really hardheaded, and they WANT to run the show. So he'll regularly challenge you.
If he does show signs of human aggression, keep an eye on him when you and the family are out there. They WILL sneak attack you when you not on guard.
If you have small kids, and you have an aggressive rooster, you may change your mind about keeping him around.
Jack