@acthc,
Just some quick reference points on coffee, since that's the only thing people seem to want to talk about about Mormons... Laughing :
The Wikipedia has a decent article on The Word of Wisdom.
Here is the full text from lds.org
Mormons aren't prevented from drinking caffeine, but again coffee, tea, and alcohol. And of course no drugs or smoking.
This does not include herbal tea, which most Mormons drink.
Some don't drink caffeinated sodas, but that's in the minority.
Oh, and the last thing which should be first, the majority of the Word of Wisdom contains positive prescriptions, not prohibitions. It's all about health, and talks about eating fruit as much as it talks about abstaining from bongs.
Second, in answer to your first question, some observations on doctrinal differences:
SDAs are pretty mainline protestants; they just believe that the Sabbath was never officially changed to Sunday. Most Christians believe that one of the fulfillments of Mosaic law at the death of Christ was the change of the day of worship.
This shows SDAs' Biblical literalism, their sola scriptura paradigm, who can't find the change of day literally stated in the New Testament, so won't bank on it. Mormons are fundamentally, at their core, not sola scriptura. They believe in revelation, in modern prophets (equal in gravitas therefore to Moses or Peter), and consequently that all canon is open; that God can give us more scripture and at times the earth has had scripture which we do not now have. That's the whole Book of Mormon thing--that while the Bible is a record of God's dealings with a small group of people in Israel, he would therefore logically have other records of other dealings with other people--it's just a matter of finding those records. That's a huge difference.
Sola scriptura also presupposes that God wants his church reverse engineered from reading the Bible. The problem is the New Testament was a post facto collection of church letters and was never written to even be a book let alone a church-building manual; so various religions choose to call its 1500 years later publication in its present 66-book form divine foresight. The LDS on the other hand say that man's role is to live righteously and to pray for direct revelation as to God's will, which is again, a huge huge difference. For Mormons, it's always about the internal journey.
For the same literalism, SDAs don't believe in ignoring the Old Testament like frankly most Christian religions do. Most Christian religions believe that all the requirements in the Old Testament were "fulfilled" (no longer necessary) after Christ--thus The New Testament (read: the new covenant.) Again, since what was no longer necessary and what was still necessary isn't overt, SDAs error on the side of safety and keep all the commandments. That means they believe the Ten Commandments are still the governing code of the universe. (Everyone else believes they're a neat ethics metaphor at this point.)
Size-wise, there are about an equal number of members of the Seventh Day Adventist Church as the Church of Jesus Christ of Latter-day Saints, but the SDA have splinter groups, so those 15ish million aren't all the same branch. That's why most charts have Mormons as the 3rd or 4th largest religion in the US, because everyone you would think would be higher is non-coagulated...
SDAs are Trinitarian, meaning they believe God, Jesus, and the Holy Ghost are one person with no physical form. Mormons believe they are 3 separate and tangible beings.
Like Jehovah's Witnesses, SDAs believe that only the righteous are resurrected spiritually, that spirits die unless resurrected. Mormons believe that spirits don't die and that everyone is physically resurrected--that everyone gets their body reunited with their spirit after death.
I'll stop now 'cause I've gotta' get to work, but really the bottom line is that Mormons and SDAs are no more connected than any other two Christian religions. Perhaps more academically similar are Seventh Day Adventists and Jehovah's Witnesses, since they're both sprung from biblical literalism
Here is a bit of knowledge for Adventist it was a Mormon who was set to the writings of Ellen White. Although this will create problems with most churches the empowerment of the Priesthood is essential to the Church and makes Joseph a real reformist since in front of witness's there was a manifestation of several from Heaven handing the keys of the Aronic and Melchizadeck Priesthood to Joseph and his followers