Yes, a rooster can hurt you, especially if he has spurs. I think you have learned the reason why Mr. Red was at auction. Human aggressive roosters are not safe or pleasant to have around. It means he's learned to see humans as part of the pecking order. And once he decides to challenge you for dominance, he will never stop challenging for that dominance. You've already lost your first battle with him. If you rehome him, you'll just be passing this problem to the next person. If you want to keep him, it means radically changing your behavior around the flock. You'll need a complete change in attitude. You need to convince him that you are the one in charge and that you are not someone to be messed with. Stand tall, walk with purpose (and a big stick), and never turn your back to him.