The shortest answer: NLA tool (in Blender or any other CG ware) is used for
REMIXING animation blocks in Photoshop style layers
REUSE complex animations - on characters with the same deform bone hierarchy.
Make animating characters way more creative and fun than linear pose to pose.
Save screen space - mixing animation strips in packed chunks/ blocks is ...
The Cell Fracture add-on would be a good start.
(The Cell Fracture add-on comes with Blender, all you have to do, is activating it via Menu -> Edit -> Preferences -> Add-ons)
Create a sphere (icosphere or rounded cube work best) with a decent polycount.
Initiate Cell Fracture via F3 - Search - Cell Fracture.
In the settings dialog under "Own ...
I'm not sure you can reduce this sequence to a single operation, to make it available to Shift R, repeat last operation. Even taking into account that the I inset operation has a 'Depth' setting, which can easily go unnoticed.
But as @moonboots has commented, you can execute the operation on multiple faces simultaneously:
Set Pivot to 'Individual Origins', ...
I use the free command recorder addon for this very thing and it works well. It has apparently been changed to action recorder and is developed by the same author. I haven't tried this new version yet though. You can find details here.
The fastest and easiest way is to uncheck Overwrite in the Output Settings. If the images of your animation still have the numbering that Blender uses to number an image sequence, like yourfilename0001.png, yourfilename0002.png, yourfilename0003.png etc. it works just by rendering the animation again.
If your animation is set to let's say Start = 1 and End = ...
It seems like Mixamo has a problem with distances. When I tried something similar to your model (just more primitive - Cones) it fails as well.
But adding spheres in place of connections worked. So the only one explanation for now I have - Mixamo doesn't know how to follow topology of your mesh. Tested with FBX Export / Limit to Selected.
You can delete or ...
You would have to iterate through all materials, get their node trees and find the principled bsdf to set its default values. Demo on how to change the Metallic value for all materials in the file:
for mat in bpy.data.materials:
if hasattr(mat.node_tree, "nodes"):
for node in mat.node_tree.nodes:
if node.type == '...