Since you are in the woods a major pro would be that the rooster could help protect the hens from predators. For cons, rooster may or may not be standoffish/aggressive sometimes they just get flustered when you mess with their hens, others don't want you anywhere near, and still others don't mind. It really depends. As far as fertilized eggs, some may be fertilized, but if the hens aren't broody and don't sit on them, they'll never develop. If you're collecting the eggs everyday you don't have to worry about finding a chick inside. I *think* that leghorns are not supposed to be broody, not sure about barred rocks.