1) Unless a different god than the one you worship exists, and they created objective moral values and duties. That being said, I function on the understanding that objective moral values do not exist. - 1) False
2) Evil is a moral value - a negative one, but one nonetheless - and thus, from my viewpoint, is also subjective. Therefore evil can exist without objective moral values. - 2) False
3) From a subjective standpoint, yes. I view murder as evil and murder exists. However, even that is subjective, as I view the death penalty as a form of murder, and thus evil, but not abortion or eating meat. - 3) True
4) Therefore, objective moral values and duties don't have to exist. - 4) False
5) Therefore, gods don't have to exist, and if they did it wouldn't necessarily be your god. -5) False
6) Your argument was that God makes morals. Morals exist, thus God exists. Then this one says that this proves God makes morals. But that was your starting point. This is called circular reasoning, on account of how it goes in a circle. God makes morals -> Morals exist -> Thus God exists -> Thus God makes morals -> Morals exist -> Thus God exists etc. 6 is only true if 1 is true, and 1 is only true if 6 is true. And if they're both false? - 6) False
8) We live by subjective morality. We have morals, and we don't even have to be threatened with punishment by a monstrous deity. - 8) False
6/8 are demonstrably false. Well done.
In answer to Dahmer: 'Because I'm not a psychopath.' We do things because we want to, because they make us feel good. Making other people happy makes me happy. Yeah, maybe it's an evolved trait because we're a k-strategist social species. Doesn't make it less genuine. I believe murder is bad because people are harmed by it. I believe most theft is bad because people are harmed by it. I believe homosexuality is good because no one is harmed by it, and it makes people's lives better.
People like you take your morals from a two thousand year old book, or claim to at least. Atheists, and most Christians - in my country certainly - view morals on a case by case basis. We do what is right and moral because it is right and moral, not because we were told to, you monster.