#15 / #16 - Clearly, it is a gerund, not a progressive form. A progressive tense needs a form of "to be" along with the ing-form, e.g.
I am reprocessing. present progressive
I was reprocessing past progressive
#16 - "being reprocessing" is not grammatically correct, I believe.
History is being repocessed. That is present progressive passive.
edit: I find it interesting that there does not seem to be an easy way out "coming to terms with history", e.g., does not seem to be an idiomatic translation to me, but seems to express the idea in English somewhat correctly.
"reprocessing" does not fit either I think this since "Vergangenheitsbewältigung" seems to me to suggest the idea of a process that leads ro something final as well.