To initiate the Eye of the Moon Plan, Madara needs to make sure that no one would be watching him or get in his way, especially Hashirama, he attacked Konoha multiple times so that he could push Hashirama to the point that Hashirama would choose to kill him and make sure he was dead so that Madara himself can prepare the plan smoothly and stealthy, and he could savage the cell sample of Hashirama during fight without being noticed. As how Madara survived? Simple, he faked his death. I mean, this guy is a powerful shinobi, and no powerful shinobi cannot fake his death because that is the purpose of the fight: to convince Hashirama that he is dead and can be left alone