Hi man. Good to see you've been able to fix the vertice issue. Below I'll try to deconstruct your findings.
1. Then I would have to see your original blend model and not the m3 file. Based on the .m3 file I received from you, I made a quick new animation to see if it deleted that, just a very plain one with movement of her right arm. Attached is a gif with the workings in the editor. I then openen that file again as an imported .m3 in a new blender window. and it still had that animation. So on your end, there's something thats unlike what I did for creation of animation. Which again, I would require the blend file for to investigate.
2. For the moment we'll let that rest.
3. That is a peculiar thing I noticed as well. I created a normal image to highlight it. The name for some reason doesn't show where I expected it to, yet the animation name still existed somewhere as it did show it in the drop down list. No scratch that. I tested it with a model of my own and the same thing happened. I closed my editor and reopened. Now the name appears properly. So that seems to be OK. --> image: Lillian_Animation1
4. I'll included some of the info from discord in here to complete this section and story. And hopefully that others may find it usefull in the future as well. :: "When I loaded it into the editor there was no attachment points and I still need to solve the issue of packing all the animations together reality is that I may need to do things the extra hard way and copy them carefully into one specific blender file.". A learning SC2 model I was using was xelnaga kerriggn and I noticed some key differences between the models. Difference 1: This one has all these sort of cages. The other has bones, but I don't see these cage like armature items on it.
These 'cages' as you describe them are from the attachment points, particle effects, light emitters and other stuff that can be set. The reason why they are not in the Lillian model is because they aren't in the file. We can get more in-depth on these later on as they are not specifically required for the issues at hand. --> Image: Lillian_Animation3 shows when an attachment point would be added that it also creates these cages. Just an FYI for the moment
"Difference 2: Above picture is the wow model's nla editor view. This is the one for xelnaga kerrigan very different and I see the sc2 animations names in it. I also noticed bones named stuff like ref_origin and stuff so I think that had to do with attachment points. For the sake of not overcomplicating stuff I will leave it at this. Although I did also have some other questions in the thread."
And the Dope sheet+NLA editor show the precise problem of there not being animations in the file. Like I stated before, I make a quick Stand animation for the model. In below image of the dope sheet you can see its there. So when we get the animations sorted, this issue should disappear. --> image: Lillian_Animation2, highlighs presence of an animation. Also to your question regarding some of the used names. Yes, they all relate to bones, and bones can be used for the mesh (and thus the weightpainting), the attachment points of which typical examples are [ref_origin, volume.xx , weapon_00, ref_turret] or from other effects such as lighting, particle effect (zealot psiblade smoke) or other.
Hey there mate. Well with regard to your question on deleting bones that have no weight painting... No, or at least, be very careful. Because even if a bone has no weight painting in relation to a mesh, it can still be an integral part of animations. They can for instance serve asdummy bones to create a certain movement, but have child bones that actually have the relation to the mesh.
A way to check this, is by having the bone selected that you wish to delete. go into 'POSE' mode in the 3D viewer and see if the bones properties [translation, rotation,scale] are changing, often displayed in either yellow or green colored bars (default display for blender) --> attachment
Again, be careful by deleting bones, as it can distort how a model animates. I wish I could give pointers on when it can or not, but this is basically a trial and error model by model. Examine the armature carefully and try deleting stuff and test weither or not the model has changed.
Right off the bat I can say that the distortions of the mesj (flying off screen) have most likely something to do with the weight attachment to the bones of the armature. From the look of it vertices aren't painted to a bone in at least some degree making them "unallocated".
See attached image, the marine shield is weight painted (red coloring) to bone "Shield" <-- case-sensitive. Vertices that aren't weightpainted are blue.
As for the textures, make sure the filepath in the editor is the exact same as the one used on the model.
If the texture filepath in the model reads: "Assets/Textures/My_Model_Texture.dds" In the editor you must also import the textures equally. See attachement.
This is what I can say from first glance of your images and explanation. Hope this is useful for you.