When you say you had your former wife served 16 days in advance, I trust that is 16 court days as required, and then your ex-wife is supposed to file and serve her responsive papers 9 court days before court. Though both time requirements are found in CCP 1005, your 16 court days is generally enforced, but the 9 court days is often not so strictly enforced. There are various circumstances that need to be considered, but I suggest you prepare for your hearing as best as you can. You are...
To answer your question, more likely than not the date you have in about a month is the arraignment date on the contempt charges. It is most likely not the trial date at all. Generally, you get arraigned and then set the trial date - or you can be arraigned and then waive time and set a pre-trial/trial setting conference date. Apart from the defense you may have as to the merits of the charge, you might have possible motions available to you as well without taking the matter to trial.
Your Australian proceedings will not necessarily supersede the Georgia orders. I suspect your pension will remain as divided but the support will be looked at under the circumstance as they are now and according to Australian law. You should consult with an attorney there.
No, you are not going to get his tax returns directly from the IRS. Your best steps are to require your former husband to provide his tax returns and an updated Income and Expense Declaration. Then you should subpoena payroll records from his work as well as account statements from his bank, so you can compare the different sources of information you then have. You are going to need a local lawyer in order to pursue these steps.
You could go ex parte, that advice is solid, but it is not much of an emergency. I would communicate with the respondent to file a Response to the original Petition, and then you can process a Stipulation and Order voiding the amended Petition. There are a lot of great lawyers in Torrance, and you could work with Stuart Bruers, Nadine Jett, or Bob Waddell for just a few names.
There are other issues, primarily are you going to have to be paying spousal support, that come in to play. If there are no orders you can just not pay, but if you are going to owe support anyway then you might as well keep your credit good.
Family Code section 2320 requires that one of you be a resident of the state for at least six months and a resident of the county you file in for at least three months immediately prior to the filing. As your husband remained in Los Angeles County when you returned to your country of birth, the residency requirements are satisfied by your husband and you can proceed with the marital dissolution in Los Angeles County.
I think you are not going to be succesful with any claim. While Mr. Conviser is correct, and you have a chance if there was an agreement, you could sue him and hope for some form of recovery but you have to consider all practical factors and not just going after him because he deserves it. You need to be better off in the end. Best regards to you.