You'd have to go off the beaten track a bit to satisfy your criteria for abandoned towns, resorts and mines. I don't think you've have the time, much less the 4WD to savour the experience of just getting there!
Plenty of rocky beaches, coves and small creek mouths along the Great Ocean Road, not as busy in February as December and January, but requires care for international drivers who are easily distracted by the wild views. For a big-sky, out-there, in-your-face ocean beach, have a look at Johanna Beach, about 160km west of Geelong: Rotten Point, a 3km slog over soft sand to a bale-blasted rocky headland, has dinosaur footprints (more too at Castle Cove over the other side). Cumberland River, south of the very busy seaside town of Lorne, will give you some insight into rocky coastline and is a comfy base for an overnight stay (e.g. cabin), as will Shelly Beach, inland above Apollo Bay in the Great Otway National Park (which we call the "Otways").
Whichever beach(s) you go to, protect camera(s) from salt spray, but especially Johanna.
• Great Otway National Park, Victoria
PS: Call in here at my place on the route to the Great Ocean Road so I could give you a map with places worth visiting marked on it.