Okie dokie, heres my two cents. First off, you have very few hens. The normal recommended ratio is 1:10 (roo

ns). To compound the problem, your boy is still pretty young. Just coming from a home where he likely wasn't the dominant rooster, hes probably super excited he has girls he can mate so hes doing the deed as much as he can to make up for lost time. On top of that, he hasn't established himself at the top of the pecking order and can only mate with a couple of them. All of that adds up to what you've got here, hens with injuries. That scab on the picture is in the typical place the roosters hold onto when they mount a hen, so he most likely didn't intentionally pick it there but inadvertantly did it with all of his amorous attention.
You're probably not going to like this, but here's what I would recommend:
Either get him some more hens or ditch the rooster. He's not going to stop this behavior for some time and you're likely to find more injuries and/or less eggs if he's only got the small amount of girls hes got now. If you get more, he'll be able to spread himself a little thinner and not constantly be grabbing onto and getting on top of the same hens all the time.
Another option would be to separate him, but thats likely to make him very unhappy (maybe even angry). Do your girls a favor and figure out a solution. Good luck!
Nikki