I have a 06 f150, It has the black textured XL plastic bumper cover. My question is can it be sanded down to a smooth finish and painted to match the color of the truck? How hard would it be to do this? What grit paper and what kind of paint?

 

Yes it is possible. 320 or 400 grit should be fine. It will take some time, but anymore agressive and you have to sand out scratches. You will then need primer and paint designed for use over plastic (some have flex addative added, some you have to add it yourself) To match your truck, you should do it in base coat clear coat, but can also be done with laquer and clear coat or straight enamel.