LM, free ranging your flock is a choice only you can make, after deciding what you can live with. My DH has never had chicks or chickens, and last year when I re-entered chicken world I got two pullets at POL and 5 Speckled Sussex pullets 4 or 5 weeks of age. I kept them in the coop and run for a few weeks, then let the two older girls out with me standing right there with them for an hour at the end of the day when I knew they would head back to roost at dusk, then a little longer, then walked away, and the day I watched them flatten and go still when a pigeon flew overhead I knew they instinctively knew what to do if a flighted predator was present. A few weeks later I started letting the SS out with them. Now they are all out all day every day. I have shrubs and trees they can hide under whenever they feel the need. The price is, no more mulch in my gardens, they have flung it out onto the grass, I have raked it back in many times, and now I'm going to rake it all up and put it in their run, it obviously is not going to stay in the gardens any more. My sedum bed is now a dust bathing bed.
When I first got them DH declared I was simply buying coyote lunch. When I first started letting them out, he was positive I would lose them all the first week. To date, the only one I've lost is the runt SS with the wry tail, who was dead in the coop one day. I am fully aware that can change in an instant, and have decided I would rather they had the best foraging life they can have even if it means they have abbreviated lives. They are so obviously, ridiculously happy out roaming the property, I can not go back to confining them unless there is some reason they can't be out, like the day last weekend we had to dig up the septic tank lids (that was some fun) and I didn't want them kicking the dirt back in the ditch/hole so they had to stay in - they complained loudly every time I was in their line of vision.
midnightroo - no reason not to leave chicks alone for the day, I do it every day, I have to work, as long as they have warmth, food, and water, they are fine.