Is shoving firestop putty around a cable in the hole a *acceptable way* of firestopping it, or does it ALWAYS require in conjunction a fire stop rated assembly, bushing, etc.
Working in commerical buildings maintenance most of my career that is all I have ever seen was firestop putty or caulk in the holes. Not sure what your refering to by a rated assembly.
Depends on whether this is just residential 1 family fire-stopping or commercial/multiresidential with actual fire-rated assembly requirements. In the first case the firestopping foam or putty is usually sufficient (depending on local codes) because the floor is not a fire-rated assembly.
On any of the inspections that I have been on and assisting (I'm not an inspector per say but all of us know what we should be looking for) the fire caulk has been used and it's a non-issue. I can't see where the putty would be any different.
You should be good with firestop putty if the whole is to big they make a firestop mat and expanding foam. We have used this method several times when we come across a pipe to big to put the putty in it.