Whether Tony or Kevin wins, it will significantly affect PRs in OZ. Already those that arrived after 2000 not getting any OZ super. Watch the space as the boat people issues and the economy plus the weakening OZ dollar will affect migrants here.
The tax offset will do you no benefit. Make sure you are sure on this route
The Re-entry permit is confirmed though I have not done it physically for MOE registration but I have encountered numerous cases but I cannot confirm if the child did go pass Pri 6. Most left before that. As OZ education start from Yr 1 to Yr 12, Coming back to continue Yr 6 will be an advantage from the schooling in SG
Yes he has to renounce one of the two citizenship at 21