Hey folks, another first-time poster. (I've read through the forum with interest but my head still hurts a little thinking through the options.)

I'm considering a RTW ticket starting in Feb and mileage monkey tells me the following route is valid:

lhr-eze-scl-ipc-scl-akl-syd-per-drw-syd-bkk,han-hkg-pek-hkg-pvg-lhr

I am in the U.S. but wanted to try to take advantage of the UK fares if I can, hence the start in LHR.

Any comments/suggestions are welcome, but I had a few specific Qs:

(1) I am torn between D and A class--I could stretch for A but saving money is always nice. I have tried to understand the rules but I'm not completely getting it: if I have an A ticket but there is no first class cabin, would I have to sit in coach, or could I sit in the business class cabin? And does the D class ticket have lounge privileges, in general?

(2) Getting the UK rate. Again, tried to follow the discussion but I must be a little slow. Seems to me I should be calling the AA RTW desk, get a locator/PNR and ask them to price it in Pounds, then actually buy the ticket from a travel agent in the UK or Canada. Is that right? If so, any suggestions on travel agents in Canada/UK that would "get it"?

(3) I am not entirely happy with my routing in S.Am. I plan to travel around Argentina and Chile, but there seems to be no sensible way to incorporate this into the ticket. E.g. I would love to fly from EZE to Patagonia and thence to SCL, but I can't seem to find a routing that would do that without wasting an overland segment. Anyone know something I am missing?

THANK YOU in advance for any advice/info, and sorry if I'm inadvertently rehashing well-worn topics.