Is there anyway to mirror a component from a selected plane, and have this new body be a completely parameterized component, meaning having all features still alive but not linked to the originally mirrored component.
Could you perform a save as of the part (which will keep all parameters).
Then mirror all of the geometry using a plane as a final feature (Instance Geometry - Type Mirror).
You can then create a reference set of just the mirrored geometry and still be able to parametrically edit it.
My starting point would be to record a journal of the above method and tweak it to your needs.
I believe all of the functions you need are covered with journalling (at least they are for me in NX8.5).