I have done some of that, guarding for a torch, under my soldering iron and the powder for sealing stove pipe into chimneys (wearing a mask). I'd never use it under a typewriter, phone or on any kind of steps. The shingles were not a problem. It was the asbestos dust. That was back in the old days before the government banned its use. Asbestos is still one of the best products for some applications, but it is not to be found any longer.I also question having a microwave transmitter near my head as safe.
Bill has a good point. Asbestos has its purposes and it is still present in some building materials. Given the risk of disturbing asbestos containing materials generations later, it is just as well that it was phased out of general use. I'd rank the typewriter deadening option as one of the worst in the bunch.
I have a stack of those in the garage, because the house is covered in them.