i would think they have to be pretty deep to be an issue, but i have seen the phaseIII dish all over ebay for $30 why not get you money back and buy a new one.
YES YES ABSOLUTELY IT CAN Depending on the severity of the "dings". If the skin is bent to far, it will throw off your signal. Remember, dishes work off of refraction from a skin. Your best bet is to check all the transponders that you should have in your area after install. Now if they truly are "dings", you should be ok. If not, you'll see readings all over the place.
Also, does anyone know why so many want to buy used equipment when you can go virtually anywhere an get a free install that actually comes with a warranty from an HSP?