"With free ranging comes great responsibility." ~ Uncle Ben Parker
Okay, so I lifted the quote in my signature line from "Spiderman".
I free range 7 hens and one rooster on 10 acres of property. People ask me all the time what is the secret to free ranging without losing birds.
The answer is, there is no secret. Free Ranging requires constant vigilance and is still, at best a cr@pshoot.
I have a webcam mounted in the coop area to document any day/night visitors to the coop. When a land predator appears in the digital cam which I review weekly, I mount a light in the area, stay awake a night or two and take it out with a rifle (assuming it is allowable by local laws).
The chickens are still locked in the coops at dusk and the coops are as secure as they can be. The coops are opened at first light or as near to it as possible.
Aerial predators are dissuaded by feeding crows. Personally, I am unwilling to directly harass birds of prey or shoot a neighbors dog unless neighbors have been profusely warned and the authorities have given me permission to do so.
After all of that, I accept the fact that a stray dog or a daytime aerial predator can take my chickens at any time. I am okay with that. To me, chickens are fun but are not pets. $5 gets me a replacement.
To date, 21 months without a loss.
I'm not bragging, that is mainly due to elements of chance. I like to think that all I do lower the odds, but in no way do I eliminate them.
All that being said, I enjoy my birds and their freedom. They seem supremely happy (they run to the car everytime I pull up to greet me and to be petted) and don't wander too far (2 acres tops).
The main key to judging whether to free range or not is in knowing the topography of your area and your neighbors. If you live by a busy road, near neighbors with free running dogs, etc... you are better off containing them to save yourself grief. A chicken with no physical boundaries will wander. That requires space to do so unattended.
If you are unwilling/unable to kill predators, I wouldn't free range. I do not recommend relocating predators.
Silkiechicken is absolutely right...free ranging is never "safe"
I hope that helps!