That's a neat way of putting it (at least broadly) in the first four pargaraphs. Thanks. I'd add that the event horizon is the boundary below which the propag

That's a neat way of putting it (at least broadly) in the first four pargaraphs. Thanks. I'd add that the event horizon is the boundary below which the propagators of causality can only move further below the horizon itself. The "unimaginably weird sub-quantum" part doesn't follow from those paragraphs, though, in the region outside the event horizon, or even a little ways inside. It is however a fair way of describing the problem of the singularity; the goal of nearly all quantum gravity research programmes is keeping the singularity from ever existing, and "weird microscopic behaviour" is a reasonable way of describing what that may entail. I made some comments relevant to your last paragraph elsewhere in this discussion.