Hens will seldom attack kids. Roosters might. If all you have is hens, you will not have fertile eggs to hatch but the kids should be very safe.
Not all roosters attack people. In my experience, mopst don't. But some do. If you are that concerned about it, just keep all hens and no roosters.
If you want to hatch your own and have a rooster, get an incubator. It is true that sex links are not known for going broody, but they are living animals. Those instincts are not always totally bred out of them. There is a thread active on this forum today about someone having to continually break her sex link from being broody. But I certainly would not count on a sex link from a commercial hatchery to go broody very often if at all.
I make my own sex links from breeds that are known to go broody. They have just as much chance of going broody as any other hen from the parent breeds. But hatchery sex links are usually not from breeds (or strains of breeds) that are known to go broody.
It is quite common for first year pullets to not molt but keep laying throughout their first winter, especially if they start laying a little later in the year. However, practically all second year hens will molt and stop laying for a while when the days get shorter.