I like to be constructive more than destructive (not to be confused with decontructive or critical, which is invaluable in intellectual persuits) so I will give it a go.
I would first acknowledge that the doctrines of the Seventh-day Adventist Church have undergone changes and developements (particularly in the earlier years of SDA history), and while we have a set of 28 statements approved by the General Conference, there is no official interpretation of these statements. What I find myself dissagreeing the most with is the interpretation of Adventist doctine. *(Note that the book Seventh-day Adventists Believe... is not an "official" church document in the sense that it was voted in by the GC like the 28 statements. And while it was published by a Church publisher, there have been several other books such as Richard Rice's Openess of God and Jack Provonsha's You can go home (not sure of title) that are not official church interpretations of church doctrines. In fact, they are seen bysome as somewhat heretical.) So when I agree with some of the 28 fundamentals, I usually offer my particular interpretation and expansion of them which may or may not go against what the Adventist scholars are writing.
I will focus on general ideas, like the S's, most of the time. These appear in no particular order.
Church/Remnant:
My confession as a Seventh-day Adventist - through my continued official membership to it and my continued attendance to a local SDA Church - serves only as part of my identity in the greater body of Christ (the Church), which incorporates anyone that acknowledges Christ as Lord of the World (believe in Christ). I agree that the bible talks about a remnant, that these are not the only people left who will be saved to heaven, but are defined by their mission to the rest of the body of Christ and the rest of the world. I find less cause for identifying specifically the Adventist church as THE remnant.
In line with the idea of the remnant as mission, or vocation, I would say that the doctrine of the remnant is next to useless when it becomes about a way of securing escape to heaven from a world headed into eschatological destruction. The doctrine of the remnant should instead breed an eschatological ethic of involvement and vicarious suffering with and for the world. That we would be so blessed to be used by God in his mission of saving all the nations. This is not disconected from the Adventist church. She has struggled with this mission in the preaching of the Word of God, which includes the Three Angels Messages, and a great social activism (which in reality should be counted as another mode and necessity of preaching the Word of God).
Sabbath:
I have alot of room for the Sabbath in my theology, but i dissent when it is made the sole issue of prophesy and eschatology (eg. Sunday Law, Mark of the Beast and the Seal of God). In some regards though, I would go further in my Sabbath doctrine. The Sabbath is ripe with symbolism of creation, liberation and sovereignty. But the Sabbath is not just symbolic. Surely if we reffer to the Sabbath in terms of "blessed", "made holy", "sanctified" then this would not open up the way for an emphasis on rigid requirements of observance, or as the Puritans did on Sunday and do nothing all day, but for the necessity of a sacramental view of the Sabbath as God's time. It is something in which we are compelled to partake of not merely because by doing this we find favour in our deity, but because it draws us into communion and fellowship with Christ and his body.
I have laboured over the problem of which day it should be (that is the necessity of the seventh-day Saturday of our current calender) in the past and probably still do. I do however see a certain importance in maintaining a continuity to the day that Jesus kept and so many other Christians have kept and also the Jews keep.
If I were to push this even further, I would embrace the legitimacy of the celebration of the ressurection on Sunday morn, as millions of other Christians do. I am experimenting with a fully fledged sacramental view of the seventh-day Sabbath as God's hallowed time with the addition of a celebratory acknowledgement of the resurrection on Sunday, the eigth day, the day of new creation, of the continuing of mission and work and of starting the week with the reminder of the ressurection.
Scripture:
It is my understanding that the SDA church affirms the Bible as the Word of God. I believe that the Word of God is Christ himself, not the words of the Bible. The Word of God IS the revelation of God through Jesus Christ, the incarnation. I agree that the Bible is the Word of God only when it is spoken as such by the Holy Spirit, when it becomes a proclamation about Christ. The Bible is in a sense more a human word which is at times breathed into by the Holy Spirit to become a proclamation, the Word, the revelation of God.
Sanctuary:
I could explain my disagreements with the Sanctuary doctrine, with the specific interpretation of a real sanctuary antitype in heaven in a physical form, the interpretation of Daniel 8:14 as refering to 1844.
Instead, I will explain what I find to be the more exciting parts of the whole idea of the Sanctuary. In the OT the sanctuary and then the temple were not just the place where one could make sacrifices for sins of the individual and corporately for the nation (which was important). It also was not just the place where the astute observer could be reminded of the plan God had for Israel's (and the nations) future (which was important). The greatest thing about the temple was that it was the place where God's presence was. It was the place where heaven and earth met. In Jesus' incarnation and sacrifice, he became the intersection of heaven and earth. This vision of the temple is fully realised when Jesus returns and heaven and earth are joined in the new earth.
This is made even more exciting when we look at the Pauline idea of being in Christ and Christ also being in us, of our bodies as the temple of the holy spirit.
State of the Dead:
I find myself agreeing with most of the conditionalist view. Immortality is not a "given" but is conditional. There is no eternal hell and most importantly there is resurrection of the dead.