Do business class tickets for OneWorld "Round the World" bookings count as full business class when it comes to seat availability, or do they only get to choose from a limited pool of business class seats?
On some routes there are no D seats made available. Eg JNB-LHR vv at certain times of year.
On 1-class flights and 2-class AA domestic flights, different booking classes are used (for economy and first respectively). Also if no availability you may be booked into lower cabin with no compensation. The rules set out the applicable economy booking class.
Sure. A waitlist doesn't guarantee you will get any seat, even if booked many many months ahead and even if OW Emerald status.
I had to reroute my DONE5 through asia instead of africa as I'd intended because no availability was forthcoming. Fortunately my travel plans were flexible enough to do so. If I really had to visit africa then I would have been forced to use another alliance instead for the trip.