As to class of service, the separate jaunt to Canada would be in promotional Y, raised to C by VIPOWs. For the rtw trip, either A or D, depending on later decisions. If in D, the AA portions would go to A by means of VIPOWs. Mileage to AA.

Going through SA wouldn't solve the problem of stopping in North America on both legs, would it?. Also it would add a continent as I wasn't planning on going to Africa on this trip.