Does this bumper have fog light cutouts pre-drilled?

No. The GT Competition bumper ships as a solid panel. You'll need to mark and cut fog light openings if you're running aftermarket fog lights. Factory fog cutout sizing varies—measure your specific light housing before cutting.

Will I need to drill new sensor holes for the lower bumper sensors?

The raw bumper does not include pre-drilled sensor holes. If your vehicle uses front parking sensors, you'll need to drill holes in the same locations as your OEM bumper or disable the sensors before installation.

Should I paint this before or after installing it?

Paint before installation is recommended. The bumper ships in primer, making it easier to sand, paint, and cure off the vehicle. Once paint is fully dry and cured, then mount it to avoid paint damage during fitment.