Just really briefly, imo the earth will weigh about the same but it is extremely difficult to tell. On the one hand you have the random addition of weight by asteroid collisions, but also you have some random gas loss over time. My bet is slightly heavier.
Second question. If the containers are sealed _and_ allowed to freely expand/contract, the weights will be the same, only the densities will change.
I'll let you know where to send the check later =p