Preface: please excuse the incorrect terminology for references to the various fixtures.
My question is about best practices for waterproofing shower/bath fixtures, in particular: between the shower flange and wall, the flange and the shower arm, the escutcheons for the "handles" and the wall, the "sleeves" over the valve stems and the escutcheons, the bath spout and the wall, and the overflow drain and the tub.
From what I've gathered from searching the internet: plumber's putty is reserved for the actual tub drain, meaning I should caulk all of the fixtures. It would also appear that I should only caulk the "top" 2/3rds of the hardware that touches the wall (shower flange, bathtub handle escutcheon, tub spout, overflow drain).
What about between the shower arm and the flange? It would seem to me that it should be fully caulked. Ditto with the "sleeves" over the valve stems where they connect to the escutcheons.
One last thing that worries me is that it would seem that water could enter in at the opening at the back of the handles (there is a gap between the sleeves over the valve stems and the part of the handle that surrounds the sleeves). Is this okay, or do I need to do something to waterproof this (e.g., plumber putty inside the part of the handle surrounding the sleeve)?