So I'm thinking about doing a mileage run, but I have a question about Visas, and I've never flown internationally.

My flight is from LAX-HKG-CGK arriving at 4:05 AM
My return flight leaving at 5:15 AM that same day

Firstly, is this possible? Second, will I have to pay the visa on arrival fee in Jakarta?

Also, my layover in HKG on the outbound is 5 hours. Can I leave the airport and go into the city for a little bit?