You have confused lack of belief with active non-belief. You started off on the wrong foot so the rest of your post is essentially worthless and does not support your position.
An atheist does not need god any more than he/she needs fairies, monsters under then bed, C.H.U.D.s, unicorns, manticores or any other magical beasts.
You are also deluded if you think humans are perfect, neither physically nor ethically. The we fall prey to sickness and old age and eventually death. Our bodies fail, we are in pain - your god must be one pathetic loser if he or you consider this to be perfection. Ethically we are equally corrupt, humanity has a history of one atrocity after another.