I agree with much of what you say here. That part I would disagree on is that intertwined debt leads to robustness because there is a common goal not to fail. From an engineering point of view I point out there where there was one point of failure in a non-linked system, now there are many. The interest will indeed be in keeping the ship afloat, but the chance of disaster is greatly increased.
Your last sentence is one which I STRONGLY agree with!