I believe it is pretty simple with DTAC too. I recently registered my DTAC prepaid SIM. They just took a photo of my passport details, did something on my phone and on a laptop, and it was finished. I got an SMS saying I was registered. Deadline for registration is end of July.
I've been a 1-2-Go pay as you go phone user in Thailand for over ten years. However, changes to my contract mean I no longer have an Indonesian SIM from the company, so it's cheaper for International roaming to get a post-paid phone contract rather than continue pre-paid. I wasn't too sure how difficult they were going to make this having heard of requests for work permits and/or 'yellow books' so I called into the AIS service centre at Hat Yai Central Festival today with some trepidation. Indeed after I explained what I wanted the young lady asked to see my passport and work permit, but after explaining I was here on a non-O marriage visa and worked in Indonesia she was happy enough to settle with my passport, my bank book and my wife's ID card. Forms were filled in photocopies signed, a few taps on the keyboard and hey-presto I was switched from pre-paid to post-paid. All remarkably painless.
Here are some random thoughts based on my experience and knowledge of Thailand rather than Laos. First, the situation on the ground may be very different from the legal situation. Assets that can't be found, or for which there is no proof of ownership, can't be disposed of by a court. Whoever has them gets to keep them. Second, the local partner will ask the court to dispose of the assets as soon as possible. If you (or your lawyer) aren't there, you can't do much. If you turn up 6 months later, your chances of getting any of the assets already disposed of will be low. Did he have a will in Australia or in Thailand (he could have one for each country)? If so, he could dispose of the assets as he wishes. If not, it will follow a preset formula and close relatives benefit, with children first in line. A child with a birth certificate listing him as the father would probably be nearest of kin. In Thailand, the executor of a will has to present a family tree diagram to the court. I don't know what happens if they simply say "no known relatives overseas." Another consideration is did he register the birth of his child with the Australian embassy? If he did, I would think the child's guardians could go after assets in Australia.