The good news is that they've began to identify you both as the one who feeds them, and as the familiar, friendly face they can trust. Giving them treats and feed from your hand too often can actually cause more problems than it will solve as they grow older. You don't want them to ONLY think of your hands as a source of food. If they do, then eventually every time you reach out in front of them they'll begin to attack your hand expecting it to contain food. Make sure you frequently put your hand in there without food and let them hop atop it, roost on it, etc. without getting food. Handle them frequently so they learn that being picked up and pet isn't frightening. It will build trust.
Also, just to prepare you, as they get to about 4 weeks of age, all chicks enter a rather flighty, skittish stage. Don't take it personally; it's just part of their natural development. As their wing feathers develop more and they begin testing them and their limits and even your sweetest, tamest birds can suddenly behave as if they're terrified of you. Be patient and calm, move slowly, sit still next to the brooder, speak softly....anything to exude calm. After a few weeks the affection will return and they'll begin to calm down. During this time you may find that the cockerels are the friendliest and most assertive of the flock, coming directly to you, settling into your hand, roosting next to you and hopping onto your shoulder or head, running up your arm....
Cockerels will go through another stage beginning as early as 8 weeks, often closer to 12 weeks in my experience, during which they may begin biting your hands and even challenging you. As those teenage hormones kick in they can get pretty rowdy. Some will grow out of it and become really good roosters. Others will turn aggressive. There are a lot of body language and psychological cues to indicate which way each may go, but it's far too much to type out and you'll develop your own instincts on the matter as you observe and spend more time with your birds. I just want you to be prepared for the normal "growing pains".