This being an old thread, don't expect too much response. It's best to start your own thread when you see a thread is dormant as this one has been for a year.
That said, chicks are very reserved about venturing forth into new territory. They are like a bather on a beach in spring, gingerly testing the water with their big toe, then wetting their legs up to the knees, then hips, etc, before getting in over their head. This is an instinct born of survival, since chicks can easily be picked off by predators.
My chicks have full access to the run after age three weeks, and the flock usually free-ranges most days so the doors to the run are left open. Yet the chicks will hang back for a couple weeks, and then when they do venture out of the doors, they hang around within a few feet of the run for the next week or two before wandering as far as the adults are.
It's important to provide food and water where the chicks are likely to be hanging out, so I would put them out in the run as well as keeping them in the coop. Your chicks will be out of the coop and exploring their new world in no time, but then you may need to teach them to go back in when night comes. Don't expect chicks to know everything!