Hi Noah and welcome to the Oneworld forum. First let me answer you with a question: why would you travel to CAI, now that BA has revised up the prices? Or do you really need to go there (then it's perfectly OK to buy also a RTW ticket while you're there).
1) You should fly JFK-SYD without a stop in Asia, because you'll be stopping in HKG on your way to LHR
2) I didn't understand your question as I don't see a LHR-LAX segment on the itinerary you're proposing
3) and 4) it's good to introduce yourself but I guess you could also directly fax to BA Cairo. Wait for a faxed confirmation before faxing credit card details.
5) You can reserve now, the ticket can be issued just before you arrive to pick it up.
[This message has been edited by JuPe (edited Jan 13, 2004).]