[Epistemologist]

Well, there are some very valid (in the logical sense) atheist arguments; these do seem rather valid (except for the second one), but they are not sound.

In the first argument, the first premise is questionable, because perhaps God would not want to stop suffering, which is not necessarily needless, because it might be a means to greater end. It could be a test of faith, for instance. Your definition of the Christian God is misconceived.

I think that the second argument is not even logically valid. Besides that, God does not need to provide evidence of His existence even if He could i.e. He wants us to believe in faith, which means that there should be no evidence in the foundation of our belief. We should thus be agnostic theists in this sense.

In the third argument, the second premise is flawed, because hell and the associated suffering is, again, perhaps a means to an end, and it is perhaps a necessary tool to bring people to the alternative of heaven.

There are better atheist arguments, but they are also unsound to some degree albeit valid. I think you gave a form of the argument concerning the problem of evil. I must say that theistic arguments such as those from natural theology i.e. the moral argument, the ontological argument, the teleological argument, the cosmological argument, and the argument from religious experience are also unsound. That's why I don't think the existence or non-existence of God can be absolutely proven, and a fideistic belief formation is in order.