Is there a way to have the flashlight on by default?

Additionally is there a way to make the cone of light larger and brighter?

I'm assuming the latter can be achieved by modifying the files in the Shaders folder, although I haven't a clue what I'm looking at at the moment...

To me it looks like the Flashlight is based on illuminating the vertexes of the Level geometry. I don´t think that can be changed with a shader.

If you use per-pixel lighting then yes, you can change it through shader editing.

There was a script for enabling flashlight, but it's disabled atm.