Not so much eliminating torque steer, but more making the effects on either engine the same, so no "critical engine". The other big advantage of counter-rotating engines was a lack of torque effects with power changes in combat. The P38 was jet like in this regard in being free of rolling or slewing effects with power changes. A very advanced airplane in spite of development troubles; in some ways the P38 was the F22 of its age (and similarly expensive).

A little more than torque involved, getting into the interaction of prop vortices and wings.
In any case, opposite rotation engines are the exception rather than the rule, and all of the US radial engines turned the same direction. Interchangeability and commonality was deemed far more important than any gains from an LR engine.

The P-38 is one of the few widely produced exceptions (and was offered to the RAF in a version with both engines turning the same direction)

All of the Cyclones turn the same way, so there isn't a left handed engine. However the accessories are not identical. One might have a hydraulic pump where the other has a generator etc, so there IS a difference in RH and LH engines on the same airplane.

The motors are marked "833 LH" and "333 RH" which I'm certain means they are bound for the same aircraft, left and right handed, but can someone more knowledgeable inform me - would they have been counter-rotating, that is one a clockwise and one a counter-clockwise rotating engine? Are they mirror-images in terms of exhaust placement, etc?

Nope. This is her sister.