Single biggest mistake that Thais could make is to allow land ownership by foreign people. This could mean the beginning of the end for Thais ever being able to buy a house or land in their own country.
Mexico has created restricted zones where foreigners can purchase land 50 kilometers from shorelines and 100 kilometers from international borders. Maybe Thailand can create restricted zones, but Thailand is geographically a fraction on Mexico.
Imagine a foreign company or someone with enormous wealth power buying out in perpetuity large chunks of land in Thailand, and one day deciding that they don’t want an outdoor market here or there, or no more street vendors here or there, or that rather than Buddhist temples on their land they want Christian churches on every block… <deleted> that! Thailand is great the way it is, where falang can complain about stupid things all day long but don’t have real power to dictate how Thais live their lives, how their homes look, or how their towns look. Also, that’s not mentioning the likeliness of sky rocketing prices that properties will undergo when foreigners become the main market to sell land too.
All around, It’s a terrible idea for Thais to ever allow unrestricted foreign ownership of land.