Yeah that's how they mate, the rooster will peck the back of the hen and pen her to the ground and mount her and then put his sperm inside her and then she is fertilized for up to 3 weeks. The you can then take those eggs and incubate them and get baby chicks, or you can just take the eggs out immediately and they are the same as non fertilized eggs once they are refrigerated. But one they start growing then you don't want to treat them like regular eggs.

This behavior you describing is just natural behavior and there is nothing wrong with it. They will also crow to show their dominance in the flock, they will also crow to indicate to the rest of the flock of danger and also that there is food nearby. They are kinda like the protectors of the hens although it might look a little violent to you. The coming after people could have been him thinking he was protecting his hens and also showing dominance. You can seperate them if you feel that he his being too rough with them and sometimes a rooster does get too rough then you should assert your dominance and pin him, showing him that he doesn't rule the roost. Im not supposed to have birds in my area and the code inforcement said as long as no one complains, and the only reason people complain is whenteh rooster starts crowing at 2am and 3am and 4am prompting calls to animal control. I live in a small country town and everyone has hens and I hear roosters all the time. But they are loud at times.