Polishing removes or reduces surface scratches, oxidation, holograms and swirl marks from improper washing. Anything that has gone through the clear coat — down to the paint or primer — cannot be polished out and needs touch-up.
It is safe, provided the technician assesses the finish, measures clear coat thickness where needed and applies the minimum correction required. The risk comes from the opposite — repeated aggressive polishing with no thickness control.
Polishing corrects surface defects. Wax gives temporary protection and gloss. A ceramic coating lasts longer than wax and makes upkeep easier. Film is the only one of these that physically protects against stones.
Not always. The body is first washed, decontaminated and inspected. If there are marks from transport or improper washing, correction is done; if the surface is sound, preparation is minimal.