This isn't supported because the tools are for creating regular game animations, not Source Filmmaker movies.

These two use cases share the same data format, but their feature sets do not entirely overlap. I've always felt that trying to support both at the same time would be too confusing for users who don't understand the internal details of these formats.

A different add-on for SFM could be created based on the Source Tools.

The image links are broken, but the long and short of it is that VTA sucks for import. Try to get a DMX decompile instead.

This is probably because one or more bones from the animation either aren't present in the model, or are muted in the Blender scene. This means that they don't move, and cause the rest of the animation to look weird.

The changes haven't left my computer yet. Please try to upload your file to another site so that I can test whether I've actually fixed the issue.

I tried that and couldn't reproduce the problem. If you have the time, please can you try to import the model into a new blend file and see if you can get it into a broken state.

In that case I'll not implement this, as it's clearly legacy stuff.

Please upload your Blend file.

Try making your meshes children of the armature in Blender. Then everything will share the same co-ordinate space.

Yes, that is entirely unsupported. I have never seen DMX encoded with XML before. Where did you get this from?

Looks like an up axis mismatch. If you have the $upaxis command in your QC, beware that it only applies to models defined AFTER that line.