1. 5 Cont F ex-YYZ 71657
YYZ-MIA-DFW-ANC-DFW-YVR-JFK-EZE-SCL-CCS-SCL-MAD-FRA-LHR-DXB-LHR-SIN-BKK-HKG-CEB(or MNL?)-HKG-AKL-MEL-PER-SYD-JFK-YYZ
a) you can have one moer segment is SA, and you can use JFK to go from SA to Europe provided you don¡¦t stay at that NA transit port for more than 24 hours. eg EZE-SCL-CCS-SCL-EZE-JFK-MAD
b) you mean MNL, or CEB?
c) You can have one more segment in Oz
d) You have 7 segments in NA now, need to remove one

2. 4 Cont ex-GIB 69496
GIB-LHR-DXB-LHR-HKG-AKL-MEL-PER-SYD-JFK-YVR-DFW-ANC-DFW-LAX-JFK-EZE-SCL-CCS-SCL-MAD-LHR-GIB
a) it is counted as 5 continent anyway, because you passed asia. So might as well add the asian segments
3. 4 Cont F ex- YYZ 66315 with only 21 segments
yyz-dfw-sju-jfk-hkg-dps-hkg-bom-hkg-akl-mel-per-syd-lhr-ath-lhr-dxb-lhr-lax-sju-dfw-yyz
a) you have have one more segment in Oz
4 Cont F ex BKK 64622
BKK-SIN-HKG-DPS-HKG-AKL-MEL-PER-SYD-HKG-JFK-LAX-IAD-SJU-DFW-ANC-DFW-FRA-MAD-LHR-DXB-LHR-BKK
a) more mile if BKK-HKG-DPS-HKG-AKL-MEL-PER-SYD-MEL-HKG-JFK-LAX-IAD-SJU-DFW-ANC-DFW-FRA-MAD-LHR-DXB-LHR-SIN-BKK, but you have 2 transcont in US: JFK-LAX-IAD, u should, e.g., change lax into DFW
4 Cont F ex GIB 61712
Option A Eur-Asia-Australia-US-
GIB-LHR-DXB-LHR-SIN-BKK-HKG-DPS-HKG-AKL-MEL-PER-SYD-JFK-LAX-IAD-SJU-DFW-ANC-DFW-LGW-GIB
this one also have the problem of 2 transcont, and can improve by inserting MEL, otherwise ok