Magsafe port coating worn away

The plastic coating of my (mid 2010, 13 inch) Macbook Pro's Magsafe charging port has almost completely worn away over time, exposing some kind of shiny metal surface beneath.

How important is this coating?

Is this a fire hazard or a risk to my laptop?

The coating is just cosmetic and surface protection for the magnets (and they do rust since made of iron).

The insulation (plastic) around the pins is important and it still looks ok to me.

There is no fire or short danger, but you might want to re-coat the magnets surface to prevent corrosion, since you are obviously in some high air pollution (corrosion) area.