Absolutely, Thank you! - totally Ok with mesh collider.
This will be incredibly useful - I could achieve a great deal with this approach !!!
I was also wandering if the Toon Outline shader is using vertex colours for the outline. Ideally I'm seeking a way to pick out the specific colour of the outline with raycast info, and then use the position and colour to create targets for particles. Essentially I'm using the outline as Edge Detect in photoshop - once 'extracted' out into [xyz] it opens the door to a host of coolest FX. If getting the vertex colour isn't possible then the uv texture colour will be fine. If the normals are inverted I can simulate toon outline and then continue from there with your suggested approach.
It's also in line with the current requirement of Mouse Pick for mesh collider I believe.
I assume that with larger scenes the absence of collider will speed things up considerably - this would be great addition in the long term.
Thank you very much!!!
Drakon.