i grill multiple times a week. unless a cut of meat has been marinated, i always use olive oil. it helps the outer most portion of the meat stay moist, while getting cooked soon enough to lock in the moisture on the inside of the meat. i ever put olive oil and pepper on kielbasa and sauasages when i grill them; keeps the casings from bursting in the heat.
salting a meat when you cook it helps draw the juices to the surface, also getting more flavor (i think this is the point of it). regardless, the only time i salt meat is when i use a chuck roast to make chili - and oh sh*t is it good. ( my chili recipe also includes beer).