Ok, Derekm,
I'll try just once. Nowhere have I said, written, implied, or inferred that insulating a hive is a waste of time. In fact I've said that the winter will be more survivable if the temperature is closer to the winter climate of North Carolina than Central Minnesota.
I can safely assume when you bed down you cover yourself with a cloth of some kind. I once got the idea I could make an emergency sleeping bag from the packing cellulose foam from shipping furniture. Great stuff, but didn't allow any exchange of air. I was warm, but soaked within minutes. A blanket allows for fresh air to creep in while the moisture laden air seeps out through the holes in the weave. I'm using the same foam between the outer and inner covers, I don't have those oblong holes in the center of my inner covers.
You are making the assumption the bees are heating the inside of the hive body. Just because you feel the warmth in the hive does not mean they are intentionally heating it. That is anthropomorphising.
The bees are balling up and heating that ball. When the USDA says the bees don't heat the inside of the hive, but ball up to conserve that heat in the cluster I don't use choplogic to justify my picture of bees sitting around a wood stove, drinking cowboy coffee and
eating cow pies.
The flaw in your observations is that a mass of bees will have to produce a certain number of calories to keep the inside temperature, and replace the numbers with new heat producers. If brood production is stopped until the relative start of spring to conserve stores, the surviving bees will have to produce that much more heat to maintain the inside temperature. Those sugars and proteins will produce more waste products than Carbon Dioxide and Water vapor. Though less bees would use the same stores, they would produce more solid wastes per capita, meaning more cleansing flights, and work themselves to death more quickly.
It's pretty obvious you didn't actually read my post, because I had already answered one question you asked, "q3: given your anser to q1 what happens to the water vapour." It goes out t'hole meboyo!
Water vapor has a lower specific gravity than air. Even if the inside temperature and outside are the same the water vapor still rises.
In fact your argument that the bees decide is ad hominem. If you cover an upper entrance with mesh 1/8 an inch (3mm) or less, they will propolize it pretty much anyway. You should leave it open. I've seen entire openings to tree hives closed with propolis, and I had one hive try to cover a hole of 2cm^2 in the heat of summer.
That's all I'm going to say on the subject, I'll let you get back to disproving Einstein.