Will this bumper cover my existing sensor cutouts, or do I need to drill new holes?

Sensor hole locations are not specified. Dry-fit the bumper against your current setup and mark any existing sensor positions before committing to cuts.

Does this bumper sit flush with the body, or does it add extension?

Exact extension or fitment offset is not confirmed in the specs. Test-fit is recommended to verify alignment with your fenders and side panels.

What prep work should I do before painting?

Sand the surface with appropriate grit, clean thoroughly to remove dust and oils, and apply your chosen primer and topcoat per the paint manufacturer's instructions.