All that you said is true.
But it could have been said in far less words by simply affirming what the Reformers and Puritans learned from Scripture itself; the hermeneutical principle that guides ALL study of Scripture: The Analogy of Faith
. Even more simply put it is the comparing of all Scripture with Scripture.
Unfortunately, there have always been those who are content to study the Bible "academically"; like a science and that is all. But "theology" in its true sense is the application of the Bible to all of life
. (Col 1:9,10)
You will find people who err on both counts everywhere you go. You will find people who are content to "doctrinize" the Bible by looking outside the Bible for evidence to show that what the Bible teaches isn't sufficient to know God's truth. And on the other hand you will find those who ignore and even deny the teachings of Scripture because they say doctrine isn't necessary. What is most important is to just love Jesus and your neighbor. Of course, HOW one is to do that is left to one's own imagination and not the inspired Scriptures from which truth itself is to be found. (Jh 17:17)