"Was wondering if the following is allowable: PEK-HKG-NRT-SYD"
Yes you can. Within Area(1,2,3), you can fly around.
I had following RTW with ANA
LAX-FRA-
HND/NRT-BKK-KIX-ICN-LAX
"If I start my journey around the world from ORD and end the trip in LAX, is that allowed?"
Yes you can. You can start and end in the same Area
I had another following RTW with ANA
LAX-MUC-FRA-DEL-BKK-HKG-NRT-
SFO
You can check ANA website, "Round the World Itineraries"
https://www.ana.co.jp/wws/us/e/asw_c...d/tk/zone.html