assuming one is successful in obtaining an extension to an SETV, now on Amnesty. Is it possible to convert that then into a non imm B visa, without leaving the country?
If you do build on her land.... Ensure all the reciepts for materials and labour payments are in your name. Then you may have the opportunity of knocking it down when things go pair shaped.
To clarify, land border crossings are limited, x2 per calandar year. If you cross using a visa, SETV, METV etc these don't count but your thailand travel history may be looked at , questioned and possibly refused entry.