The wooden part of our coop is western red cedar, made from fence pickets....it hasn't seemed to harm anyone in the 2 years we've used it. And we have put Eastern red cedar shavings in as bedding when we were cutting up cedar trees. And that didn't seem to harm them either, but it's a fairly...
Yes, I think you can use pine needles, or chipped wood. Whatever you have. Why buy something when you have a free alternative...
My husband is a wood turner, and I have lots of hardwood shavings, and so I use those on the floor of my coop. For the nest boxes i use grass (hay) left behind...