I registered myself (all in English) as the Housemaster of my wife's house where we live. The supporting docs I uploaded were:
1) Copies of pages 1 and 2 of the wife's blue book.
2) Copy of my wife's ID card.
3) Copy of my passport ID page.
I received my userid and password within 24 hours. This was at Buriram, your IO may apply different conditions to register. When I get a new passport, I won't be registering again and will continue to use the existing account. Your passport is part of the TM30 you submit anyway, so that should be OK. As for registering from overseas, I don't know the answer for sure but I can access the TM30 website from my browser with my VPN set to Singapore. All I would suggest is that you try it yourself. The app (called Section38) is much more user friendly than the website. I only used the website to register initially and have used the app for ALL TM30 reports. Hope this is of some use.