I'd like to stay neutral on this. Nehru was younger, sure, but Patel wasn't fighting hard for leadership. He was realistic, and knew that with his indifferent health, he might or might not be able to take the strain for a prolonged period. He gave in to Gandhi's wishes with complete calm acceptance, with tremendous maturity, but his acceptance of Nehru as Prime Minister did not stop him - never stopped him - from giving Nehru a tremendous scold from time to time, in public. For instance, in the meeting that Manekshaw, then a very young officer who had accompanied Menon to Kashmir, when the question of what to do was put to them, Nehru started rambling on and on about international relations and the march of history. Patel interrupted with an impatient,"Do you want Kashmir or not, Jawaharlal?" He got a mumbled assent. Patel turned to Manekshaw and said, crisply,"You now have your orders." And Manekshaw marched out, and being in the DMO's staff, moved the waiting troops to the planes and out to Srinagar.
There were other anecdotes, too.
Fair evaluation.
Yes, that's right.
Jinnah believed that it was the whole plan, no chaffering, or nothing. Nehru announced at a press conference on 10th July 1946 that delegates to the constituent assembly would vote according to their conscience. For Jinnah, that was the last straw. He informed the government that the League stood for Pakistan, uncompromising and without further discussion, and he launched Direct Action Day.