Bright star,
Your summary looks right to me. Maybe some day the AA RTW desk will share the revenue splits for non-AA/BA flights with BA and then the NTP earnings for those flights will disappear, but it seems not yet.
I gather from what I've read here that Cathay is the second best airline to book with. But it's a distant second, and a TA may be better. There are a few on this board who book RTWs. Fam, please post your experiences.