Mike, the suggestion you made above may be helpful in overcoming your current conundrum. If we talk about the "physical world", time and space are both physical dimensions. We live in 4 dimensions, 1 (temporal) + 3 (spatial). In Einstein's equations of relativity, time and space are treated in almost equivalent ways (crucial difference: observers can only move forward in time). In astronomy, there is no practical difference between observing what happened millions of years ago and what happened millions of lightyears away from us (as I've made clear on another thread). Also, all physical processes extend over both space and time. If we understand anything at all about the natural world, this understanding has to deal with both space and time. Now, suppose we keep that idea (physical dimensions = time + space) in mind and then take seriously the follow statement of yours, with which I wholeheartedly agree:
In this statement, the "physical" should actually include the time dimension. Moses' authority would have applied within the world of the original audience (!), in which spiritual takes precedence over the physical world (which is largely unknown in time and space). I have no problems with the Bible operating within the "status quo" of that picture, in order to clearly convey salvation-related matters.
Now, I perceive both YEC and your MC view as arriving at conclusions that stem from inadvertently projecting modern concerns about "physical history" onto the ancient text of Genesis. This is undesirable because, as you said, the ancient audience of these Scriptures was primarily concerned with the spiritual (or "spiritual history", already linking the spiritual to the time dimension). When we eliminate that particular projection of our "modern" mindset, we can appreciate fully not only the imagery of heavenly storehouses of hail and the spiritual aspects of disease, but also the wisdom and truth expressed in the Creation account and Adam & Eve, without having to "butt heads" with what scientific research can tell us about the natural world (across time and space).
[made edits for clarification]