A Canon within the Canon

So I’m reading Paul Zahl’s Grace in Practice, and have gotten to the section about “a canon within the canon.” Essentially he’s arguing we should read the Bible with the grain instead of against it. To do this we are to fit most every Biblical bit into the categories of Law and Gospel. He argues if we don’t do this, but instead take all Biblical verses as of equal weight we are interpreting the Bible in an Islamic way. Ignoring the diversity within Islamic exegesis, does this make good sense? Doesn’t categorization such as this force things to contort into uncomfortable shapes that do not fully express their actuality?
And further, taking this critique of “canon within canon” a bit farther, can it not also be applied to canon itself? Can we not say that holding the Bible up as authoritative destroys the uniqueness of individual spiritual experience? Or is it only if we assume all spiritual experience must conform to Biblical models that we get in trouble? Can there be for Christians experiences and practices that are non-Biblical that still are Godly?
I think there can be. I think one of the greatest dangers the church faces in confining the Gospel to pre-existent models instead of entering into the dynamism of the Spirit.We are afraid of new acts of grace because they may not look like our present knowledge of grace. We are like children learning. The first dog we see is a Yorky, thus we assume all dogs are Yorkies. Then when we see a St. Bernard we do not recognize it as a dog.