Getting them to work does require a flash from the dealership. The dealership will have to contact GM directly to obtain the info necessary to reflash. Make note that your fog lights should come with a one time use authorization code that the dealer needs when they contact GM. Getting them programmed should cost not more than an hour labor ~$130ish.
Most common option is to wrap it. Rock chips can definitely be fixed without a total rewrap by the vinyl shop. Could be free touch ups if u ask them nicely and they would be able to wrap the sensors with them still being fully functional. I heard it was a big no no to paint chrome.
of course the best option would be to do a complete bumper swap but that is a pricey trade off.