~The PrimaLoft is PrimaLoft sport, and there are two 1.8oz layers as you suspected.
~There is no drawcord or elastic at the waist.
~The hood on the hooded version is helmet-compatible, which means it *should* fit over any helmet you would be wearing.
~I don't have the average weight of this particular garment, but the Insulight Hoody (which has 2 oz of insulation) weighs, on average, 1lb 5 ounces.
~The jackets are, indeed, made in the USA, right in Newark, NJ to be precise.
Please let us know if you have any other questions!
Wild Things Retail