It isn't a RTW award -- perhaps that helps to clarify it. The rules are extremely simple: mileage limited (50K in your example), 1 stopover per city and 2 transits per city (including stopover), must use at least 2 non-AA airlines in OW. Otherwise no limit on number of segments. However the hub structure of OW makes it difficult to overcome the 2 transits per city rule (e.g. CX only has 1 hub, so with this rule you can fly into HKG and then have 1 HKG-somewhere-HKG flight and you have now maxed out HKG and can't route through there ever again). But you could then fly HKG-BKK-SYD-NRT-MEL for example, unlike on paid OWE which prohibits backtracking continents. It is a very flexible award. For Europe you can be pretty creative (with hubs in DUB/MAD/HEL/LHR as well as minor hubs in MAN and BCN -- you could easily do over 20 segments in Europe and it would use up maybe 10K miles).