1. As I understand it, the metalic pads result in an electrostatic attraction between dust and wheel, not a 'surface stickiness'...hence coatings dont really help much. They may make it easier to clean, but not the attraction.
2. Changing pads is fine, and really the only 'solution', but when you are under the 'free' BMW maintenance, that can be a challenge....
Keep it as simple as possible...but no simpler.