@Anonymous
I was wondering if there is a way to convert camera object into an editable spline. I know it is a non-scaling object, but can the camera icon, target cube and plane, and connecting lines turned into just splines so it can be modeled furtherly?
No, as far as I can tell the camera Icon is not directly accessible to the user other than to change it's size in the viewport (via Customize>Preferences>Non-scaling Object Size.) On the other hand, if you crank up the size of the camera in the viewports and screen capture the side and top views to use as image guide planes, it becomes a fairly simple modeling task to model it yourself using primitives and edit poly modeling techniques. The target cube and plane are really simple so personally I would model a free camera (or physical camera if that's what you want) and add those later.
Since your goal is to use it as a starting point for further modeling, this seems like it could work for you.

