I did the same this trip, I had a flight booked at the 55 day mark to Vietnam, which I used. Stayed there for a week and then re-entered Thailand, got another 60 days, however I was questioned about when I would be leaving and if I had a flight out of the country which I showed.
They are definitely scrutinising all extensions and re-entry of tourists
Mate, definitely come over and do some trips first. Get a feel for the different areas.
Don't come with pre- conceived ideas.
Start learning some Thai words as soon as possible.
It's not a perfect place to live, but it is far ahead of Australia for livability at this point.
You can own a condo freehold, but if you want a house and a yard, garden etc... then yes it's either renting, or enter into somewhat murky and risky, shelf company arrangement which I don't recommend.
No I had a return ticket but it was 3 months in between, I also had a ticket out of Thailand, to Vietnam. Then a took a ticket from Viet and back to Thailand, then leave Thailand in another 20 days.