A Few Quick Questions About Purchased 5E Content

Short answer: Yes and yes. Longer answer: When you buy a module, you're effectively unlocking a template for which to create a new game with. You select the module from the game creation page and it will assign everything that is in the module into the new game. This module is always available after purchase. So you could make as many different copies of the game as you want. As a Pro user, you can use the Transmogrifier tool to pull content from the module and place it into another one of your games or move items from another game into a game using the module. Once a game is built using a module, it behaves just like any other game on your account. This is a wiki page for  Storm King's Thunder that may answer any other questions you might have regarding how purchasable modules work.