Docility in roosters is not attributable to breed alone, if at all.
Bantams can be just as aggressive as large fowl, just doesn't hurt as much...lol...maybe.
When a small child is involved, best not to have roosters at all.
Broodiness has nothing to do with a rooster being present or not, they will either go broody or not.
You can always get fertile eggs from someone else if you do have a hen go broody and want her to hatch out some chicks.
If you really think you need to have rooster, read up on chicken and rooster behavior as that's the key to managing aggressiveness.
@Ridgerunner has a great write up on rooster behavior, maybe they will chime in?