Isn’t pantheism the same thing as atheism?

[Belacqua]

Since Seax wrote:
“God would not create a universe with laws opposed to His Will.”

^^^^^So, this is the keyword right here. Seax says His Will. So, the pantheist god has a brain.
Since a pantheist thinks of the sum total of the universe as god, I suppose they mean that all this is his brain.

So in your view, will necessitates a brain. Is this a human-like brain? Or can it be different? Generally God's will is not thought to be the product of a material brain, but maybe you have other theories.

Many Christians say that God's will is not like the will of a changing, thinking being with a physical brain. God, as the Form of the Good, attracts us to himself insofar as we desire the good. So "God's will" is just this attraction we have toward goodness. It isn't like some guy sits around and decides what he wants to happen. 

Then, there is the question as to what does he think all day long, is he walking around in his own universe at the moment and talking to other “gods”, ....
I would need a large number of pantheists to ask such questions.

If God is nature, then God isn't occupying nature as if nature were a space you could move around in. That would be like moving around inside yourself. 

I don't know about pantheists, or which ones you're referring to, but in classical Christian theology it's generally said that God does nothing. As impassible and perfect, God has no motion or change. 

“Only the most naive Christians see God as anthropomorphic. God is the Ground of Being, and the First Cause, and has no human-like body. This part is the same for Pantheists.”

==Seax had written:
“Christianity is essentially dualistic in most ways, though many Christians, especially Catholics, hate the term. They believe that God is separate from nature & regard much that is natural, and in my view healthy, as ungodly. “

I don't know who Seax is, but he's fairly fuzzy here. Maybe it makes more sense in context. 

For example, I hope he's not saying that something is necessarily healthy because it's natural. I would find that hard to accept. 

You're right that there is a great deal of variation among Christians. God as Ground of Being is transcendent to nature, though I don't think that "separate" is quite right here. Many Christians think of God as being absolutely imminent in nature, with God present in every particle and cell and inch of empty space. 

Generally speaking, Gnostics think that matter is evil, but many Christians think it's all good to the extent that it reflects God's goodness.  

^^^^^this seems to be mostly correct. Some christians seem to have the view that this universe did not exist. The jewish god did a “creation ex-nihilo” and poff, this universe existed and then the story of Genesis starts up. There are variations of course. Some christians think that Genesis did not happen and they borrow the version of history as layed out by the sciences (Big bang theory, cosmology, Evolution theory).
So, there is a major problem of synchronization between various sects of christianity. Ditto for judaism, islam, mormonism.

You're right, there is a wide variety of opinion among Christians. According to Genesis, after God made matter he said it was good. So Christians who like that would think that matter is good. 

Are you wanting to say that the creation story is something which differentiates pantheists and Christians? That might make sense.