The scene on the train in South Africa, where Gandhi is thrown out.
The behaviour of the conductor clarifies to Gandhi the attitude of whites towards coloured people. For the first time he realizes the injustice of the British and their empire.
His arrival in India.
The crowd of people show, who much influence and support Gandhi has in India. Probably all of them have the same opinion as Gandhi and without their suoort, he wouldn’t have reached his aims.
The salt march.
The conversation between Nehru, Jinnah and Gandhi, when they talk about Indias future.
The fast during the riots.
Gandhis behaviour in this scene proves the absolutness of his attitude. He made no compromises.
The assassination scene at the end of the film.
Except of a typo is your list of the key scenes very detailed. Very impressing that you still know so much