Hey man, first I want to say I appreciate your dialogging with me, and if I offend you in any way I want you to let me know so I can apologize. Personally, I find this kind of discussion to be fun and important. ..
First, I want to ask how you think someone you can get a physical Father God from the Bible alone.
Second, how can you say the Bible existed before the Nicene creed since the New Testament hadn't been solidified until later, 397 at the council of Carthage.
Third, what evidence is there that there were Christians who didn't understand God as a Trinity mentioned in the New Testament? Specifically, where in the New Testament are you getting that? Sure, the New Testament doesn't mention the Creed, but it seems a stretch to assume there are any Christians mentioned in the Bible who disagreed with a document that hadn't been written yet. Where did you get that idea?
As for the rest of the books the Mormon church uses, including the Book of Mormon, why should you assume there is anything worthy of acceptance as scripture since they are at odds theologically with the rest of the bible, and there is no historical evidence that the claims made in the Book of Mormon are in fact historical? All of the New Testament documents can be shown to have been remarkably preserved, and in as much as they address history they have been verified to be correct. The book of Mormon hasn't been verified by any historical or archaeological evidence.
As far as the idea that the "form God chooses to take" not being a significant difference, I can't see how you can say that. The Christian God is a self existent being who created everything there is and holds it all together by His will. There is nothing that exists that He didn't make. There was never a time or place that He didn't exist. He is the originator of all things and time. How is that not sufficiently different from the Mormon God who has a body and a beginning to require that one must assume a different identity?
It certainly seems to be a vastly different concept to me. On the one hand, the Christian God explains how everything got here, on the other, the Mormon god leaves the question open. (perhaps I'm wrong about this, if so, please educate me)
Your whole argument about plural wives seems to be based on the idea that the only reason it is wrong is because it would be difficult for the man to manage a household with more than one woman. I guess I can't really offer an argument besides to say that I completely disagree, and that my understanding of scripture's teaching on marriage is that it is always between one man and one woman. The rest of the complications are merely reflections of the wisdom of God's command.