Pepperman35... have you tried editing animated doors in nifscope? My animations after nifskop do not work. Even if you just rewrite nifs with pe anim without making changes, the animations immediately die. Not sure why, but any static mesh animations done in 2013 max with ck plugins after nifskop won't start.
There is only 1 line inside a havok animated .nif file, to link to the .hkx 'behaviour' data. (where the animations are stored, compressed)
So, there isn't much Nifskope can screw up.
However, just like gamebryo animations, they use node names and/or id's for linking the animation data to any object.
If you change those, by hand or copying or replacing a mesh ... and you brake that link.