Wicking? Is it a barrier or does it allow drying out? Does wool actually win ?
Wicking doesn’t make waterproof but facilitates drying, or wetting. Ideally you want one way wicking, if there is such a thing, away from the wall, with sufficient ventilation to ensure the surface remains dry.
When I was learning mountain craft as a youngster and before a lot of modern fibres, I was taught that wool is the best insulating layer as it works when wet.
Heavy duty thermal linings and wool curtains can help reduce heat loss on solid walls. Tapestries could add some extra insulation too but not as much as proper curtains.
Definitely. That’s why I’m gradually replacing curtain poles with curtain tracks 