Probably better of talking to thai immigration, cost nothing to ask the question there and get the right options available, if you have a thai partner , just buy 1 Ria in rural area can be as cheap as 65k baht pending on location and build a house that suits your needs, it's very doable with 100k Aussie dollars.
The authorities always want to know where you are, so every motel you go to want a copy of your passport and they are linked to immigration, it's different when you live here .
What she wants and what she gets all depends on how Naive you are, just do little Reno,s here and there and space it out over a few years , then you will have an idea if she can be trusted,, it's a bit rich going for a full Reno in 1 hit,, unless you have children to her or been with her for 5 or 6 years and you didn't get her out of a bar.
I think a fair bit of what you can and can't do on these posts, is all hearsay and Chinese whispers, I asked at my local immigration office in kamphaeng Phet and they told me I can do what I want at our residence which included 3 Ria of corn and 4 Ria of rice but said don't help the neighbours, whether this is his opinion or law I don't know. But I asked the question and that's what I got.