wagonwheeler,
You are correct about the tension on the chain. The chain is long and it will run hot and stretch. As you say, just keep an eye on it. I too, adjust by feel with a bow.
There has been some conversation about bows being inherently dangerous. While they are dangerous, so are any chainsaws. Again, personal experience dictates our belief system. It is my personal belief (I can only speak for myself) that bows are no more inherently dangerous than bars in the hands of an experienced sawyer. I have years and years experience running chainsaws and in particular, bow saws. Having said that, I realize that I could make an error tomorrow. I cannot express enough about how I stay focused when running a saw. I am at heightened alert continuously. It is sort of like when I climb (mts. not trees). A mistake on my part would most certainly be fatal or at least, nearly so. At the end of a day, I am frequently exhausted and it is from concentration, not physical exertion. I believe concentration is the key to safe operation of any power equipment. Clearly we cannot do anything about equipment failure as that is frequently unpredictable. A quick safety check of equipment prior to starting and then a review of the saw at each fueling is always wise and something I practice. Guns don't kill people, people do. Saws don't cause the injury. Haphazzard operators do. Carelessness or fatigue is the culprit. That is my belief system.