I HAVE STOPPED THE CRASHES!!!
I have done major progress and I will likely finish soon.
I was opening up a monster by another modder who had actually used OpenCOLLADA when suddenly I noticed, that even though I definitely selected openCOLLADA in the export options, that was being ignored by both of my files and instead exported as fbx. I quickly learned that it was because there was some kind of conflict between my fbx-plugin and collada so I tried turning off the plugin completely and finally it actually exported as collada with zero bugs on my little bendy cube!! animation and everything fine.
The monster was a little messed up however but the fact that I was able to import it in model viewer without crashes, and on top of that the animation was playing (though looking messed up) is a major advancement for me and I have a good feeling I be able to fix it in not too long
as my monster is messed up and I dont wanna spoil it I give you a picture of my little bendy cube being bendy
feels good man