I agree with the first and last ones. I don't think Luffy would have trained for the two years. Luffy only gets stronger when he has to save someone or fails to save someone. Like on water 7, he only got stronger because he wanted to save Robin.
I still think Whitebeard would have stayed to face the Navy and Blackbeard pirates because he is well known for not retreating from a fight.
I also don't think that the pirate alliance would have been formed because Luffy only trusted Law because he saved his life after the war. I also believe that Luffy would not have waited two years to go to the new world and therefore he would have not met Law at Punk Hazard
Wow thats some great analysis thanks for dropping by.