Will this cover my fog light cutouts, or do I need to modify those holes?

The Viper style is designed with its own aggressive lower intake and fog openings. You'll need to cut or drill to match your existing fog light housings if they differ from the stock Viper layout — the cover does not come pre-drilled to your specific setup.

Does this bumper have sensor cutouts for parking sensors or radar?

No. This bumper ships as a solid panel without pre-cut sensor holes. If your vehicle has OEM sensors, you'll need to carefully drill or cut openings to match their location before installation.

Will this fit with my lower valance or air dam?

The Viper design has a lower, more aggressive profile than stock. Compatibility with aftermarket lower valances depends on the specific valance design. Measure the underside clearance and gap profile before purchase to confirm fitment with any existing lower aero pieces.