you can stay in Thailand for uptown 90 days on your first arrival, you will get another 30 days, which you can further extend by another 30 days, when you come back from Australia. No need for re-entry stamps etc I think you're over thinking this :-)
maybe I am mistaken but if you are intending to stay 60 days in Thailand then go to Australia and come back for 30 days, or more, then you can do it all with visa exemption and 30 day extension
You can come to Thailand and get a 30 day visa exemption on arrival, you can extend this for another 30 days for 1900THB if you're staying more than 30 days. If you leave and go tp Australia, you will get another 30 day exemption when you return, which you could also extend for 1900THB. If you plan to stay more than 30 days your airline may ask for proof of onward travel within the 30 day limit, you can buy very cheap one way tickets online with budget airlines to neighbouring countries to assuage their concerns, but generally if you explain your itinerary they will be okay. Very very rarely will Thai immigration ask for onward travel details, but it does happen, but again if you explain they will generally listen. What alerts their suspicion is repeat travellers with multiple extensions etc
ye I have had to go through the mill getting my wife a visa for the UK and Europe a few times and it's horrendous. I wonder how many foreigners would be happy if somebody chose to go to their home country and treated everyone as if they should bow down with gratitude for them being there?
I find the whole mindset that Thailand should be grateful for your patronage quite bemusing. You weren't invited, you came and asked if you could stay, and they agreed. Your pension isn't going to get them setting off fireworks. Be grateful, not arrogant.
I have never had any issues entering Thailand, but I have noticed that they have started asking me questions about how long I intend to stay and where etc, so I got a longterm visa. In my opinion they are only doing what they should be doing to police the people coming into their country. Personally I would get a proper visa before you have a problem, rather than wait to get refused entry.
It’s an absolute nightmare. I gave up and asked a “friend” to help and they made it happen for 2000THB. Some people are just lucky, I have to buy mine.