Several questions about TransformControls

I have some problems implementing TransformControls, somehow they appear to become children of the objects they control and they will be intersected in a raycast and become effected by the outline post-process when the object they control is in the selection list.

Maybe someone can answer some questions about them:

  • Am I right they become a child of the controlled object? Or is the other way around?
  • How do I keep them from being raycasted?
  • What is the best practice to assign a new controlled object?