Commsec, page-4

My understanding is that CommSec is a division under the CBA banner. The Australian government guarantees deposits up to $250K but am unsure if that applies to foreign residents. It is generally accepted that the Australian government would step in to guarantee a bank if there was a run on same but there is no written policy on that. The RBA ensures the Banks have adequate capital reserves, thus capital raises from time to time.

T + 2 settlement is self explanatory imo. IE: Sell Friday 13th. March and your funds are credited to your nominated bank account on 17th. March, being 2 business days after share was sold. I would not think you would need to be an Oz or Kiwi resident to open an account but if you are a foreigner withholding tax would be deducted from any interest earned on bank deposit. Commsec web site should answer most questions.