Only problem with this is it would require a second camera and renderer. With Torque3D, this just isn't going to be a good idea, would lag to hell. Which is why we don't have split screen.
No. The reflections are done in the renderer. A reversing camera would require a second camera, as explained before.
Many games that have mirrors and secondary cameras run them at very low res and with very low details, its obviously not off the table and in my opinion very possible.