Can ATF level affect engine idle..???
 

while adding/removing ATF to get the level just right, I noticed something quite strange. When I added more fluid to get it to max level, the engine idle rpm would jump up & down constantly from 450 to 700?? this effect was more prominant when I put the gear in D.

then when i pulled out about a half quart, the RPM fluctuation got a lot better. Am I imagining things here, or is there a reason for this?? obviously i noticed this because when i went for a short drive and waiting at a light, the car would stumble and shake like she was going to stall (never did)

I've never seen one stall due to high fluid level. It'll just start puking it's guts out, idling merrily along the whole time. On a M119 motor, it would be more likely a problem with the throttle actuator than anything to do with the trans.
Gilly