The popular atheist claim, "You must only accept scientific evidence as truth," is self-defeating (destroys itself) because that very claim is not a scientific claim, it is a philosophical claim.
That's a stupid argument and it's not common. The only time I have ever heard that argument is people promotting invisible sky fairies trying to claim that other people make that argument. Its simply not true. Also, the claim itself makes no claim to being scientific, therefore your "self defeating" proposition is empty and holds no merit.
This claim presents a major double-standard among many atheists, because the Multiverse Theory
You're the first person I've ever heard make say this, therefore isn't very common. Also, "fine tuning" of the universe is a religious claim and has nothing to do with science or atheism.
In order to make this claim, there must exist an objective (3rd party) standard (law or umpire) of morality
You can figure out on your own that slavery is bad? You can't figure out that forcing a rape victim to marry her rapist is bad? Wow. Please stay away from women and children.
All of your claims are nothing real. They are stupid arguments that Christians pretend atheist make. They're straw men. Also, rape is bad, since you seem to not have figured that out.