Ok, it looks like Fact #5 was, in fact, untrue. I was able to fit a little less than a quart of water in the radiator. What I believe happened was the black plastic lip down inside the filler hole had coolant on top of it, giving the illusion that the radiator was full. So far the temp has stayed perfect doing a little rough driving and stopping so I believe at this point the problem is fixed. Now I hope I did not cause any damage to the water pump, etc by not having enough fluid in the system. I guess I may have a very slow leak because everything I can see is dry and I have never smelled antifreeze.