Re: Anodized tuners and other miscellaneous parts.
Anodized aluminum will hold up much better than a powdercoated aluminum part. Anodizing is a chemical process that physically hardens the outside of the aluminum. It's not a coating or a plating, but a transformation of the actual metal surface. It will be more chip, solvent and wear resistant than any powdercoated finish (both finishes will scratch). It's not an invincible finish (show me one that is) but it is extremely durable. Also, unlike PC'ing, it's a "finish" that adds zero thickness to your part.
The majority of guitar hardware is cast potmetal and has an electrically applied plating that is NOT anodized. The only metals that I'm aware of that can be truly anodized are aluminum and titanium. If more manufacturers used aluminum you would see more anodized parts, but frankly it is much more cost effective to MIM un-anodizeable mystery metal than it is to cast/forge/mill AL parts.
As for refinishing the majority of the hardware out there, I agree 100% that powdercoating is the way to go, both in durability over the cheapo factory plating and expanded vibrant color options.