Why can't i delete the unecessary parts of an FBX import?

So i've made an animation named Spinhover. I want it to just be a generic animation that i can apply to lots of single rigidbodies.

I made the animation in blender, by animating a cube. And this is the result. I've got it working fine and dandy now, and i can aply it easily to any similarly simply structured object (such as a keycard) but i don't need the cube, or the Avatar, i think. nor do i need that extra redundant copy of the animation.

And while i'm at it, i'd also like to pluck it out of that folder and place it, alone, into somewhere else. Like a subfolder of animations. Also i want to rename it.

But i can't seem to do any of these things. Why not?
If i rightclick on one of those pieces, the delete option appears in the context menu. but selecting it just silently fails with no explanation or apparent reason

What's going on?