I commend your attention detail, particularly contingency planning - ie: the worst-case-scenario (container collisions, storms & groundings).
I would, however, like to temper the discussion with the observation that: most cruising consists of “interminable stretches of utter boredom, punctuated with moments of shear terror.”
By which I suggest that you may be expected to spend 60% of your cruising time at anchor, 30% sailing in light air, 4% in heavy air, and perhaps <1% “in harm’s way” [OK, someone offer better proportions
].
Using Failure Mode Effects Analysis (FMEA) we multiply the likelihood of a failure occurring by the severity of the consequences, to arrive at a risk quotient.
Risk = Likelihood x Severity
Hence, even a fairly drastic consequence (of damage or failure), presents a small(er) risk, when multiplied by a very low likelihood.
I’d consider many other characteristics of any particular keel configuration (as you have already summarized), ahead of hitting a semi-submerged container.
Regards,
Gord