Bad76,
Interesting thought. I'm curious how running the ground through the switch instead of pos would "put less strain on your power window switch"? The same amount of current is going to run through the switch regardless of which direction it's going. And in this case, the current will be a small fraction of the current it has been carrying.
Someone before mentioned this saying that it would eliminate voltage spikes to the switch. Again, when the switch contacts touch, you're going to get a spark/spike regardless of which side the positive is on........