Will these mount at the factory rocker points?

Yes. These bolt directly to existing factory mounting locations on your Tundra. No drilling or frame modification needed.

Do I need fasteners to install these?

Mounting hardware is not confirmed in the product listing. Test-fit before committing to fasteners, and refer to your vehicle's service manual for torque specs.

Can I use these as-is or do they need prep?

Aluminum can be left bare or painted to match your truck. If you're painting, prep the surface and use an appropriate primer for metal. If you're keeping them natural, they'll develop a patina over time.