I'd much rather see people who research and plan well before they ever get an animal also...it's important to know what you are getting into, what you will need to be successful and how you want to manage your flock.
The problems start at the point at the highlighted text. When it is all said and done on this Earth, you will only know something if you try it for yourself. Books are a great starting point but they aren't the definitive source of all things known or experienced...they too are merely the author's experience or info from a few very controlled studies.
Fortunately~or unfortunately, according to your personality~our backyard is not a controlled situation and has so many variables as to render it useless as a lab...but experiment we must. If we want to find what works in our own little backyard, we have to try things....yes...we may even want to try things that may~ in maybe 1% of birds~ cause respiratory problems.
So far on this forum I've gleaned that we cannot use:
Pine shavings~toxic
Cedar shavings~also toxic
Hay or straw~impacts crops and also fatal...imagine that.
Paper towels~chicks eat them and get...Oh...look, it's "impacted crops" again.
Sand~chicks eat it, fill up on it and then can't eat their food and die of starvation
If I were to believe everything I read in books, mag articles and on this forum, I would be trying to raise my birds suspended in the air so they don't come in contact with
anything that could harm them and I'd
still be obsessing over the quality of the air in which they were suspended!
Having said all that, I've used pine shavings with absolutely no ill effects and used cedar shavings in small amounts in a very well-ventilated and large chicken house and got a few birds that started wheezing. Those birds were rehomed and the rest of the flock did very well...but I did not repeat the cedar shavings experiment.
Straw or hay never were eaten by any flock I've ever had(maybe penned birds do this? Mine free range, so their crops are already full of grass and such).
Never used paper towels because I have always used pine shavings....never a chick or bird lost all these many years.
Sand? Never tried it.