BKK-BOM-HKG should not be a problem as CX flies this route four times per week and you have one more segment to use in Asia.

Visiting CPT will be a bit of a problem. You have used three of your allowed four segments in Africa. The two choices you have are to buy another segment on you OWE ticket for A$500 in business or A$200 in coach. If you go the coach route, the problem you may encounter is that some agents/airlines will say the extra segment is the last segment in the continent while others will let you choose the segment. The difference is between two hours in coach from CPT-JNB and a four hours from JNB-NBO. Another alternative is to buy a one way fare locally, CPT-JNB, for ZAR773 (A$170) in coach on CE (Nationwide).