You are dealing with living animals so anything can happen, but I believe it is better to let the chicks start free ranging with the flock as soon as they come off the nest.
Bad things can happen, especially if you have a very wimpy broody, but what normally happens is that another chicken will get too close to or threaten a chick, mama will severely reprimand the offender, a lesson will be learned, and the other chickens will then leave the chicks alone. It seldom takes more than one or two reprimands before the whole flock has learned the lesson. And don't interfere with mama. She needs to teach that lesson.
I've seen posts where people think a rooster is more dangerous to the chicks than the other hens. I don't agree with that. A good rooster will protect all members of his flock. But if mama needs to discipline a rooster, she usually will unless she is wimpy.
To me, the benefits of mama raising them with the flock, other than the convenience, is that the chicks normally develop better immunities if raised with the flock and mama takes care of the serious integration issues. They will still have to handle their own pecking order issues when they are weaned, but these tend to be much less severe than integration issues. I think the dangers to the young chicks is less with mama around than the dangers of integrating partially or fully grown chickens.
