Question

2- What happens to the solubility of gasses in solution as the partial pressure of that gas drops?

Answer 1

Generally it falls. Think of it as an equilibrium problem. You've got dissolved gas as the reactant, and gas above the solution as the product. If you remove product (the gas above the solution), you will drive the "reaction" to the right -- some of the dissolved gas will turn into evaporated gas. Le Chatelier tells you this, among other things.