Last time, I was in Sydney for 14 days as well. I go to Woloogoon, Kiama, Blue Mountain, Hunter Valley and Port Stephens. I missed The Entrance. You must visit there.
In fact, 14 days for Sydney is very good. You can go to many places. Just Sydney near the City, you can go to the Zoo, go to weekend market, Visit Opera House, relax at Darling Harbout, try the Chinese Seafood. Sooooo many things you can do. If you can drive on your own is even better!