lpeterman,
Thanks for your nice offer. Here are some more ideas for you.

You can do both ATH and DXB, and you can accomplish this in one of 2 ways.
1. The London prohibition only applies to free segments. So if you wanted to fly LHR-ATH, you would have to buy 2 additional biz segments (there's no 1st on that route) at $400 each. These 2 extra sements would still contribute to your 20 segments maximum.
2. You can buy a separate RT ticket (probably cheap) LHR-MAD and go on the IB flight to ATH, without having to buy extra segments. IB also has only a biz class section.

As for the return from SWP on CX, here is the rule we're all talking about:

ONLY 1 INTERCONTINENTAL DEPARTURE AND 1
124N . INTERCONTINENTAL ARRIVAL PERMITTED IN EACH
125N . CONTINENT EXCEPT AS FOLLOWS:
128N . * 2 PERMITTED IN ASIA WHEN 1 IS A TRANSIT
129N . WITHOUT
130N . STOPOVER OR ON DIRECT SINGLE PLANE SERVICE
131N . BETWEEN THE SOUTHWEST PACIFIC AND EUROPE.

I agree with Darren that the routing is not allowed. Others have interpreted this rule in 2 ways, depending on where you put the non-existent comma

2 PERMITTED IN ASIA WHEN 1 IS A
TRANSIT WITHOUT STOPOVER
OR
ON DIRECT SINGLE PLANE SERVICE BETWEEN THE SOUTHWEST PACIFIC AND EUROPE.

2 PERMITTED IN ASIA WHEN 1 IS A
TRANSIT WITHOUT STOPOVER OR ON DIRECT SINGLE PLANE SERVICE
BETWEEN THE SOUTHWEST PACIFIC AND EUROPE.

I never even thought of option 1 until I read it here. It never hurts to ask, I guess. If you do manage to get it ticketed, I see what you mean about A class availability on the nonstop HKG-JFK. However, the 1-stop (the one that stops in Vancouver), which leaves a few hours later, seems to have decent availability. You can ticket that one, and use it as a backup. Or you can change it to the nonstop at any time. They seem to make it available close to departure, and there would be no fee for the change.