I am having a heck of a time checking the fluid level on my TH400. Is the level extra low but splashing back on the bottom of the stick? I don't see a really thick, generous coating on the stick, it's pretty thin. Is it a false reading?

So, if the car was cold, and I yanked the stick with the motor off (having sat long enough to cool off), how high above the full mark would I expect to see the cold, more viscous fluid?

Doesn't make a difference where it is cold, it should be checked with trans hot, car idling in park. If its a chrome stick, yes they can be hard to get a good reading. If you are checking it repeatly it might help to wait a min or two as fluid draining down the tube can get on the stick and give a false reading.