Hi Dave,
On the insulation question. I wonder if anyone has ever used as infill the small styrofoam peanuts they use when packing boxes for UPS etc. shipping. This would be a free and environmentally friendly insulation alternative. It might take some time to collect them. When you talk about wool, I assume you mean from sheep but there is also a product called rock wool which is a mineral and supposed to be a good insulator. Earth sheltered homes are interesting. Check our "permaculture", they have done a lot of research and work in this regard already
I hope to build a barn in about a year using the same principles that you mentioned, cutting by hand and using locally cut timbers and as many natural products as possible. I think you are on the right track. Keep going.
Haz
