I recommend the Book of Mormon as it is one of the most introspective books you can find. It comes across much clearer than many other religious books like the Bible (even though the Bible I recommend as well) because it has a common narrator who fills in the gaps for you and helps you understand the links between stories. It also is fairly scientific in its premise-- if you do an experiment by reading some of it and…
I'm going to take a page from Bezos and "disagree and upvote". I think the Book of Mormon (which I will hereafter abbreviate as BoM) is worth reading once, even if you are just curious about its contents. But I would not elevate it beyond elaborate fiction as its adherents do. I have been meeting with Mormons from our local ward for several months now, and these are my conclusions after long hours of research into bo…
I would say, though, that the idea that more manuscripts necessarily implies a more reliable textual history is incorrect. The textual history of the Book of Mormon is incredibly simple, substantial parts of the original manuscript and the entirety of the printer's manuscript (a copy made of the original for purposes of printing it) both exist. For the New Testament there are no "autograph" manuscripts (original manuscripts) and the earliest manuscripts are at best a century after the originals. Reconstruction based on all of the numerous NT manuscripts really only serves to get you back to the point the the BoM text is already at, and not even quite there. See Royal Skousen's Book of Mormon Critical Text Project for more on this.
It took hundreds of years for trinitarianism to be adopted as a consensus, and prior to (and also after) the great creeds there was substantial disagreement about the nature of God. I wouldn't put too much stock in them as a doctrinal buttress. See "Voting About God" by Ramsey MacMullen.
Again, kudos for all your research into Mormonism, which I find to be a fascinating tradition, even if I now seriously question its truth claims.