I just went through the 2005 on afcis and I have no Idea what you are refrencing from the posts. I agree that outlets get smashd all the time by furniture and case fires. I agree that aluminum wireing causes fires from poor connections. I dont agree at all that a low current circuit with devices mounted on the ceiling are in any danger of physical damage that could cause a fire. I dont agree that the low current devices are likely to cause a fire. I doubt a smoke detector/alarm ever caused a fire. This is my point
I read an article a while back (I don't remember who wrote it) that stated one of the largest causes of fires in NM installs is the staples being driven in to tight. This has nothing to do with the utilization equipment and everything to do with the circuit.