TRRR,
It seems the questions have been answered about the rollers (collectors) for the center rail. I like the track change idea.
No, not another transformer, just another connection with a lock-on on the inside loop and opposite of the other. That will provide better track power distribution and connect the other outside rail if you place it opposite.
Lets leave the Lionel engine issue and the switch operation issue aside until you get the SD70 running correctly.
