1. Has the development agreement been registered? Has the POA executed in favour of the builder to sale the flat of the building constructed up on the land of the land owners been registered? If yes, then you can buy the flat from the share of the builder. however, you are required to make a thorough search of the property and also verify the agreements before deciding to buy the flat.
2. Landowner, being the GPA holder, can execute a GPA in favour of the Developer but as per the Supreme Court Judgment passed in the year in case of Surya Lamps .............Vs. State of Haryana, the said GPA in favor of the developer is required to be registered since the developer will further sale the flats falling with in his share.
3. No proble. The said two sons have executed POA in favour of their father authorising him to deal with their shares of the property which includes executing a POA in favour of the Developer. In fact all the documents including the POAs are required to be scrutinised carefully before deciding to buy the flat.