Mormonism is a little different from the Christian Platonist since we tend to make more of a difference between God and any individual. So unlike Platonism (or many forms of Buddhism) the difference between God and us is never really effaced. Thus deification for Mormons is rarely taken as a kind of mystic union but much more being like Christ in the flesh. So in a way Mormons are actually more like traditional Christians despite our rejection of creation ex nihilo in that we maintain that gap. That said some Mormon theologians like Orson Pratt did move more in the Platonic direction, albeit with more of a materialist thrust. However on this point their theology never really caught on.

The idea of spirits as material actually has a long history in Christian thought. The traditional notion of ghosts as sort of like a gaseous substance really is remnants of folk traditions where spirits are material. You find this in several significant Renaissance philosophers. Part of this is, I suspect, due to it being very hard to make sense of what an immaterial substance is. People tend to (erroneously) think it’s still spatial but just invisible. The very idea of the weight of a soul some atheists like to attack Christians with is really critiquing these folk traditions within western Christianity. Typically the atheists in question don’t realize it’s at odds with most mainstream Christian theology. (There are other problems as well – since it might be a soul just weights very little or doesn’t interact gravitationally)

Regarding sources for calling these doctrine, again doctrine is a little loose in Mormonism. The focus tends to be more on practice. However D&C 130 & 131 cover several of the points. The meaning of (4) is a bit more debatable as it’s typically a teaching taught outside of canon by both Joseph Smith and Brigham Young. The King Follet Discourse is usually appealed to it although some Mormon thinkers like Blake Ostler reject the King Follet Discourse as a means of grounding theology. In any case it appears to be a common teaching from the Nauvoo era of Mormonism through contemporary sermons even if not technically part of canon. Whether it counts as doctrine probably depends upon how one defines “being like God.” I left it intentionally vague since I’m not sure we know what it means.

Regarding (6) Mormon canon has expanded quite a few times, most recently with additions to the Pearl of Great Price. D&C 138 was added early in the 20th century. I think most Mormons treat things like the proclamation on the family as quasi-canon even if it hasn’t been canonized yet. I don’t quite see why you’d see this as non really accepted. From what I can see people get really excited every General Conference hoping new big changes are happening. I’d say that many recent changes from the mundane (changes to the priesthood quorums of the Seventy) to the significant (opening priesthood up to all males in the 70’s) have taken place. I think most people are always hoping for new canon changes.

It’s also the case that Mormons expect there to be many future new scriptures. So only around ? of the Book of Mormon was translated. (116 pages of translation was lost, but also at least half was sealed and not allowed to be translated) There’s also expectation of scriptures to appear from other groups.

1. rejections of creation ex nihilo in preference to organization out of always existing matter
2. essential embodiment of God the Father
3. spirits as essentially material rather than immaterial as in Cartesian or Thomist views.
4. ability to be like God in a more robust fashion than traditional Christianity allows due to (1)
5. emphasis on important of authority for ordinances (although that’s mainly a break with Protestants)
6. belief in expanding canon
7. belief that Christ appears to the Americas soon after his death

There are lots of other differences but those are the core ones.

The tradition that terrestrial bodies and resurrected bodies don’t have blood seem to be just speculation. Yet I’m not sure it’s speculation that’s wrong. While I’m sure our resurrected bodies will be similar to ours, I’d also assume many solutions arrived at by evolution for function are replaced. So hopefully we don’t have blood vessels in the way in our eyes, our intestinal track isn’t so dependent upon the right gut flora, etc.

For me, if something is a step two, it cannot be a foundation doctrine, much less the only one that matters. Even obedience to God must come as a second step, since a person must decide on some way of knowing what God is saying to her.

Of course, no one knows what doctrine is, as evidenced by the post and comments but not to worry, there is only one doctrine that matters: obedience is the first law of heaven. If you are obedient to what current leaders say is doctrine, you will do just fine. If that bothers you, Mormonism will be a struggle.

Ken Jennings: “What is Mormon Doctrine?”