I bought two Sebright chicks last weekend from a woman who said they were five weeks old but they seem slightly older to me. She still had them in the house with four other chicks in a round tub about 2 1/2 feet diameter, with a heat lamp and just enough room for the chicks and the food and water. When I got them home, they were TERRIFIED. They had no idea what dirt, trees, fresh air, the sky, sunlight, other chickens, ANYTHING was. I felt really really bad for them. They are slowly adjusting but so far are scared to death of the other chickens except they bully the heck out of the smaller chicks, and they are really skittish toward me. I really hope they end up adjusting okay because it took me quite a while to find silver sebrights near me.
My point being, of course there are risks, but getting the chicks used to "chickening" early helps yield a well adjusted chick. They learn to socialize, do chicken things, where they are in the pecking order, etc and they also can develop physically by being able to run and fly and bounce around. These new Sebrights could barely fly up onto the roost since they had never been able to use their wings before.