All cotton for us and microfleece and some poly/cotton blends or polyester for some outerwear & dri release fabric for sports.
Somehow, we don't have trouble with cotton and sweating. Normally, I hate synthetics, but soft, cushy microfleece blankets are great. I always hang microfleece things, I never put them in the dryer. They air dry very fast, too.
Sort of. I wash my clothes in cold water after sorting lights and darks. Towels, etc., get washed in hot water. I don't wash my clothes but hang them to dry instead. Clothes shrink too easily. We don't tend to buy things that require dry cleaning.