Well this form is obviously dead, but for posterity if anyone comes across this on Google with a similar problem - I concluded that it was the motorized "soft close" striker assembly and swapped it out - and that wasn't it. Threw in the towel and went to Lincoln. Turns out that in addition to the multiple motors controlling the trunk lid lift/close, latch release, and soft close feature - there are FOUR SEPARATE control modules (located behind the trunk light in the upper passenger side of the trunk) for all this BESIDES the BCM - and one of them was malfunctioning.

Conclusion - the Fusion/MKZ with the "soft close" feature has the most over-thought, over-engineered, and functionally retarded trunk system ever devised by committee engineering anywhere.