More information regarding the world MC:
There are two variants only - the More and Qantas cards only. There is no Zero or Breeze world MC.
The annual fee for the More version is $190, and for the Qantas version is $220.
You also get SPG gold after 1 night's stay at a SPG property, providing that booking is charged to the world MC.
There is also the up to 12 months travel insurance etc.
Minimum credit limit is indeed 12k. For those with an existing account and have a >= 12k credit limit, there is a form to fill out and fax back and it is just a product transfer. For those with less than 12k you will need to apply for a limit increase first. A new card number will be issued.
Of note is the following in the application form:
If you have paid an annual fee on your current account type; no part of this fee will be refunded.