AGPA purchase registration with full consideration payment

It is general practice for real estate consultants in Hyderabad to purchase property on AGPA and then sell it in future and execute sale deed. Such AGPA and subsequent sale deed transactions will ensure that real estate consultants will pay net stamp duty of 1% to 2% instead of 6% to 7%. Even I am planning to buy property for short term and planning to sell in 3 months to 2 years. Can I purchase property on AGPA by paying full consideration to the seller? My questions: 1.What happens if the seller you executed AGPA on me die before I execute sale deed on new buyer in future? Can I still execute a sale deed? Is it legally valid? 2. Can I execute Sale Deed in my self in future if I am willing to hold this property for long term as I have paid full consideration in the past on AGPA registration. 3. Does original seller (who executed AGPA on me) has any rights or authority to cancel my registered AGPA even though I paid full legal consideration (market value) and which is already documented in registered AGPA Thanks in advance