The most recent version is 2.7.1. Please update.

If there are still errors, please say what they were.

It will work fine, just make sure that the undeformed mesh has decent thickness.

I suppose you could if you with a bone for every vertex, like you had, but it would be much easier to export it as a vertex animation.

If you want to keep the width of the curve editable, use a curve and array modifier like this[pasteall.org].

You're defining the widge of the ring with an animation, but the exporter by design removes all animation transforms when exporting the reference mesh.

You need to get the mesh into the state that you want and then hit the Apply button on the armature modifier.

I suspect that this will fix the other problem you're seeing, which is probably due to vertex welding.

Or just upload your blend file. :)

Do you mean after expor or after compile? Your QC may be set up incorrectly.

BlendParams aren't used for vertex colours, they are used to define which texture in a blend material appears on each vertex. My test model uses the material materials/blends/bamboo_path001.vmat.

No idea these days. Whatever there is will be on http://developer.valvesoftware.com/.

No, because that would change the layout of the armature. Every time you connect a bone to its parent you are also rotating it, which will mess everything up when you come to combine it with other animations or reference meshes.