layers:
  - name: test
    type: solid
    masks:
      - inverted: true
        name: My mask
        feather: [10, 10]
        opacity: 50
        expansion: 20
        path:
          type: ellipse
          width: 1280
          height: 720
          position: [0, 0]

First off I am surprised you are having problems with the examples on the website. I will investigate on that. Note that you need to have an active composition in order to create layers. Otherwise you can always put the layers in a composition:

compositions:
  - name: Your Comp
    layers: ...

I am working toward adding more error messages and better breakpoints. Version 1.1 should give you more indications of where the problems in your script are. 

About the "work until it fails", yes, it is basically how it works for the moment. Again, the script is being improved to give better results when an error is encountered.

About the way you envision working with it, well, it's exactly what it's built for. Separation of concerns and modularity. 

If you ever have problem with something specific, feel free to paste the text here and I will gladly help you fix it.

Glad to know you like the script! The way you use it is exactly the reason why I built it ;) Now about the examples, I've recently added a gallery section to the website. There are not as many as I would like to be, but you will be still able to find some examples there. More will come soon.

At the moment, the focus is on adding features and correcting bugs, but I will soon make more videos and tutorials explaining the different ways to use Hyle.

And if you did something clever with Hyle that you'd like to share it, you can always use the pastebin and send the link to @HyleScript!

Glad to know you like it so far! I currently don't have access to Red Giant Plugins, so I am not able to test it but as long as plugins us standard properties controls (sliders, dropdowns, angles, colors, etc.), Hyle should be able to affect it. Although, every plugin has its own way to behave with After Effects, so every plugin brings its share of complexity and unpredictability. I will try to get my hand on some Red Giant plugins tho to make Hyle able to communicate to it.

Unfortunately no. Since Hyle is built using ExtendScript, Adobe’s language for Creative Suite software, it is not possible for Sony Vegas to communicate with this language.

Thanks for noticing, a new version of the homepage will launch in about a week or so with a lot of fixes and more informations about the product.