Thanks for the additional information.
1) Custody Battle
Have you confirmed the DNA evidence is solid? Run your own DNA test?
Your affidavit to stop her taking the children overseas, should focus on the best interests of the children... showing their well-being and happiness, etc. would be improved by staying in Australia... and providing factual reasons why...
Are you happy with the access for you that is currently proposed? I assume you would be able to manage more access if she stayed in Australia, and that is what you will be trying to get...
You could try a free local legal community centre to assist you...
2) As there has been a property settlement... everything financially between you both was settled as at the date of the property settlement in Jan 2014.
As the source of your stress, occurred within your marriage... there is no legal claim you could make.. other than highlighting all of the conduct (i.e., misconduct) of your X... when you were making submissions to the Court regarding your property settlement... as this has already been finalised... there is no way to recover your losses within the Court system.
I wish I had better news.