This thread is exactly what I needed, being new here... it has already answered a great many of my questions. Talking to either travel agencies or airlines resulted in getting contradictory data, so it's good to find people who know what they're talking about. I'll post my specific questions on the DONE4 I've been considering soon. I think my original itinerary is still valid, having looked at the info available here.

So, I've listed the more generic questions I was left with after reading this. And I figured being new, I was the right target demographic to add to the questions.

As for the sticky thread, I'd suggest adding something on buying RTW tickets in different countries, the rules that apply and and possible caveats one needs to bear in mind. Also, is there a definition of what "transcontinental" means in the US? Obviously, there's a fairly obvious intuitive definition, but I was wondering whether there's a formal one too. The "selected cities" wording makes me wonder...

Are there any benefits from choosing a certain airline on codeshares? Some flights offer a choice between booking on QF or AA, CX or IB, etc. Anything to be gained from that?

What exactly is the significance of a stopover? What are the advantages of connecting within 24 hours?

What are the chances of getting bumped from First or Business traveling on AONE/DONE? Although it'll be obvious that you're traveling on discounted First or Business fares, how often will you be singled out? Can the ground staff see you're on a RTW and pick on you because of that, or will you be put in the same pool as other A/D passengers? I've flown on D fares a few times and I've never had a problem. What are the routes where "real" long-haul First class is available. It seems to me that these are becoming fewer and fewer.

What's the best way to argue with reservations/ticketing if the need arises? Do you refer to the "star file" and specific lines? There seem to be a few of these around; what's the proper nomenclature to use?

Those are the questions that I still have. Unfortunately, these are real questions and I can't help much in answering them in the way others have done when posting questions and answers here. I don't know whether all of these questions belong in a FAQ here, as the answer may simply be "it depends," being too situation-specific, or the question might be far too labor-intensive to answer.

Anyway, many thanks to all for having provided so much information already!