Better to apply for DTV in Australia they soft power. Then your wife applies as a partner. It's better option than non o ,it's 5 years for 10,000 bht other conditions but easy and only have to show 500,000 bht in your bank once
Go see a dentist and get a 6 month treatment plan get those choppers looking good. Use the dental plan to apply for DTV in Australia best visa by far for you
if you do the extension it has Ben reported here you have to show all the documents same as your original application. But if you do the extension in immagration remember your 90 day report is 14 day before or 7 days after the reporting date. So when is you extension date that's what you need to check if it is in that period don't worry about 90 day
Ok at what the requirements are just submit what the embassy is asking for. You obviously qualify. Keep it simple if they want something more they will ask. But most people getting requests for more info are giving wrong criteria. Follow exactly what they want. Good luck