G'day Steve,
You are right about the historic Adventists and their reliance on the teachings of Ellen White but I would like to propose tha there are in fact four main groups within the church not including the sub- groups.
The Historic Adventists beleive much of what the church taught from its beginning in the 1860s to the the 1950s. This group teaches that Christ had a sinful human nature and a very perfectionistic interpretation of the investigative judgement from 1844. In this group santification in the life of the beleiver is heavily stressed. Some Sub-groups beleive in the Arian herecy and many of these groups and sub -groups can be found in independent ministries and the internet.
The book "Questions on doctrine" was published in 1957. The book was printed as an answer to questions raised by the evangelicals Barnhouse and Martin and their studies of Adventism v the theologians of the Adventist Church and their understanding at that time. Many of the so called pillars of Adventism were watered down or changed 180% as seen by the Historic Adventists. The doctrine of the Trinity was more formally established and the doctrine of the sinful nature of christ was dropped. Other sectarian doctrines such as calling the other churches Babylon and the doctrine of the Remnant Church was also changed. There was also more openess to the protestant Gospel of "Righteousness by Faith".
These events became the catalyst in forming two groups within the church with those to some degree holding to remnants of reformed and developed Historic Adventists and those rejecting altogether and becoming evengelical christians. The evangelicals are supported by " Good News Unlimited", Spectrum Magazine and "Atoday'.
The fourth group are "the liberals"although they are a small group are separate from the others because of their teachings. They may hold to evolution and not beleive in the virgin birth. Some of the clergy belong to this group but run into problems in their ministries.
So there is quite a spectrum of beleifs within the church my grandmother wouldn' t attend the church for ten years because she beleived it was all to confusing for her. She told me in the old days the church would confront apostacy from the pulpit but now she said to me "You don't know what the person sitting next to you beleives.
Barry