Can I step over pink wool like insulation in the attic?
The only place I would step is on the ceiling joist. The only thing that holds the insulation is the drywall. If you step on it you will probably end up back in the room below. A foot print on the insulation that covers the joist will not hurt anything. Before I would remove the old dry wall, I would mark the location of the ceiling joist on the existing drywall and install 1/4 inch drywall over the old. I have done this several times and it works fine.