"And yet the delusion persists among the public, that US foreign policy is driven by a desire to spread democracy."
There is also the co-equal delusion in the West that other countries want democracy (they just don't know it yet).
I'm not sure that we disagree, yet.  I have to give some more thought to the categories you propose.  I'm not quite sure yet that what you label as "dictatorship" isn't more of a tyranny, at times; that would add two more categories, anyway.  Back to school for me to look at economic systems and government regimes.