Do these mount at the factory rocker points, or do I need to drill?

They mount at factory attachment points — no drilling required. Bolt straight to the existing holes on your extended cab.

Is the black finish paint, or will it scratch easily?

Powder-coated steel, not paint. More durable than factory paint and much more resistant to chips, salt, and UV fading. Minor scratches will show the bare steel underneath, so touch-up with a black touch-pen if needed.

Do I need to buy hardware separately, or does everything come to bolt them on?

Fasteners are not confirmed in the package — have stainless or grade 8 bolts on hand that fit your factory mounting holes. Hardware store bolt matching is cheap insurance against rust at connection points.