Darren

Here are the changes that I would suggest, knowing for the most part what you want but if I accidentally changed something crucial then my apologies. It's going to be hard for you to do Dubai and there are no through flights from LAX to South America except for SCL and EZE. From New York, Dallas, and Miami, there are obviously many.

Trip 1

CAI-LHR
LHR-MRU (buy one way ticket to Seychelles)
SEZ-NBO
NBO-JIB
JIB-NBO
NBO-JNB
JNB-SYD
SYD-NOU
NOU-BNE (buy ticket to Port Moresby)
BNE-AKL
AKL-SYD
SYD-JFK
JFK-DFW
DFW-ANC (is this a mileage run or do you really want to go?)
ANC-DFW
DFW-JFK
JFK-SFO
SFO-LAX
LAX-LHR
LHR-CAI

This takes you from a gang of tickets to really two. The MRU-SEZ ticket is reasonable. Seem to remember published fares at about $200 or $250 and frankly I dont remember if local travel agencies sell consolidated or not. Might never have asked.

Trip 2

CAI-LHR
LHR-HKG
HKG-CMB
CMB-BKK
BKK-BOM
BOM-HKG
HKG-JFK
SCL-IPC
IPC-SCL
SCL-GIG
GIG-SCL
SCL-JFK
JFK-SJU
SJU-PTP (ticket to CAY)
PTP-SJU
SJU-JFK
JFK-SFO
SFO-LAX
LAX-LHR
LHR-CAI

First, I changed the order of continents so you go from Asia to South America. Added Bombay and removed the need to buy a ticket to Los Angeles. You obviously will still have to get whatever Asia and South America tickets you need because unfortunately it's tough with the limited hubs. If you take the SFO-LHR direct or if you buy the ticket to Los Angeles then you free up a segment that you could use to go to Torino if you choose (it leave from Gatwick though so you would have to take the bus if you dont stay in London). Doing DXB would be tough under the circumstances of leaving from Cairo. Doable but tough and would take a full reroute of what you have come up with. Frankly, I dont think it's worth it. If you free up two segments then you can go to Istanbul a lot easier. Can't remember if you have been or not.