I mainly use it on motorcycles. Are there any areas, other than brake systems, where use is not recommended? Also, since I read it contains metal powder, does that mean it may act abrasively like a polishing agent?

[Areas Where Use Is Not Recommended]
This product is not recommended for the following components:

Brake components such as pistons or pad contact areas, where lubrication may compromise braking performance

Wet clutch systems, including internal clutch components

Internal engine parts designed for oil-based lubrication (e.g., crank bearings, as noted previously)

[About the Metal Powder Content]
Bell Hammer Metal Grease contains ultra-fine metal powder particles that act as friction modifiers.
These particles help form a smooth lubricating film on bearing surfaces and contribute to reduced wear.
They are not abrasives in the typical sense, and under normal usage conditions, they do not accelerate surface wear—
rather, they serve to minimize it.