This isn't a good place to ask for help with general modelling. Here's what VDC has to say on the matter: https://developer.valvesoftware.com/wiki/Viewmodel#Creating_a_viewmodel.

It would be a lot easier to list the things that aren't supported. It's a good idea, I'll try to do it at some point.

Nope. There are other tools that can import them and at least one of them can probably export to a format that Blender understands. :)

Thanks, I'll get this fixed.

Looks like a Blender bug to me. There's no code of mine running at that point. You can work around the issue by removing the armature modifier from the mesh...or just delete the object when it appears. :)

The exception couldn't be created correctly, but it seems to be genuine. Somewhere in your advanced flex controller block you have two elements with the same ID. (Or, less likely, there's a collision with an element in the exported data.)

You can reload scripts by pressing F8. Press it twice as Python doesn't always reload all files in a module folder.

You can't start Blender from VS due to a limitation in the Python Tools'[pytools.codeplex.com] UI. You'll need to start it up then attach. But I absolutely do develop and debug there.

There is also a test module that demonstrates how to get automated tests working. Unfortunately the tests require a special build of Blender which exists as a Python module instead of an executable. It builds with VS2013 though, so it's not a huge hurdle.

If Blender crashes while debugging, make your own build with "Python Safety" enabled. That build will be slower but will throw exceptions instead of crasting on invalid Python access.

If you're still working on this, you can now fork the Tools' code on GitHub[github.com].

This is unlikely to be related to the Tools' exporter.

I can't repro anything like that with 2.5 and 2.74. Can you provide a blend?