I walked around with a King James Bible every time I went to church. I spent a year learning about The Old Testament in seminary, and another year learning about The New Testament. The Book of Mormon itself directly quotes the King James Bible, errors included. It absolutely is a flavor of Christianity, no matter how unappetizing you find it.
The entire story in The Book of Mormon is about Jews who fled the old world, settled the Americas, and worshiped Jesus. The only substantive divergences from Christianity that Mormonism has are additions.
But go ahead and detach my criticisms from your religious belief. After all, that is what faith is all about.
You start getting into 'no true Scotsman' arguments at this point. Is the only "true" Christianity that which professes the Nicene Creed? Teaches the Real Presence? Other?
However, just because the Mormons are using the same words (from the same book) does not necessarily mean that they have the same theological concepts:
> This brings me to an example which does involve error of a sort sufficient to make successful reference to the true God doubtful. In the post on Geach linked to above, I cited the 2001 decision of the Congregation for the Doctrine of the Faith that Mormon baptisms are not valid even though they seem at first glance to make use of the correct Trinitarian formula. The reason for the decision is that the Mormon conception of God is so radically different from the Catholic one that it is doubtful that the words truly invoke the Trinity. It is not Trinitarianism per se that is the issue, though, but rather the radical anthropomorphism of the Mormon conception of God. As an article in L'Osservatore Romano summarized the problem at the time:
[…]
> The Mormon conception of deity, then, makes of God something essentially creaturely and finite, something which lacks the absolute metaphysical ultimacy that is definitive of God in Catholic theology and in classical theism more generally. Even Arianism does not do that, despite its grave Trinitarian errors. To be sure, Arianism makes of the second Person of the Trinity a creature, but it does not confuse divinity as such with something creaturely. On the contrary, because it affirms the full divinity and non-creaturely nature of the Father, it mistakenly supposes that it must deny the full divinity of the Son. It gets the notion of divinity as such right, and merely applies it in a mistaken way. Mormons, by contrast, get divinity as such fundamentally wrong. Hence their usage of “God” is arguably merely verbally similar to that of Catholics, Protestants, Jews, et al. They can plausibly be held not really to be referring to the same thing as the latter, and thus not worshipping the same God as the latter.
There's some 'inside baseball' differences on what people's practical day-to-day beliefs are, and what the actual theological underpinnings are. Most folks will not know about them.
Your argument is that because Mormons don't believe in the Trinity, that they don't believe in omnipotence and omnipresence.
This argument is false. Mormons believe that the Trinity is two living immortal men (Elohim and Jesus), and one omnipresent spirit.
They are also very inconsistent with the idea, since originally they did believe in the Trinity, but later Joseph started preaching the three beings doctrine, and had the Book of Mormon edited to reflect it.
But all of this is splitting hairs. There is no point arguing whether Mormons worship the wrong version of God, because God is fiction in the first place.