eligible 72 hr transit?

hi, landing 05:00 in Beijing on 30.9.2018 from munich. departure to melbourne at 12:05 3.10.2018 (have confirmed seat and approved valid Australian passport. looks like total stay time is 67 hours. am i able to travel to great wall? also, if staying at hotel, they will register me with local police, correct?

just want to make sure no issues when i arrive. thanks in advance for advice!