I have a small collection of export mausers (i.e. 3x'09s, 1x08, '93, '95, '98), and would not hesitate to fire them, given their excellent condition--but I don't for the sake of wear and tear, and need to obsessively clean every part.
I own ammo and dies for every rifle that I have. As for the mausers, I would only buy them for shooting if the bolt matches the action. The DWM gunsmiths were the best in the history of the world and as long as the rifles are in original configuration, you'll never see a better fit in those rifles: not to mention the weight, strength, and quality of the steel put into the actions during that time period is unmatched to this day. You can tell from across the table if a bolt is mismatched, because it just will not have that "ahhh" slide, fit and lock that you want, and which is why I'm addicted to these rifles.
As for wartime rifles, I've been warned to avoid late war productions, as the quality control slipped as Germany began to lose the war.