I don't think that restoring resources will work in this game. If that was the case, when we build rare mines, we will have an inexhaustible source of that rare material. We just wait for it to regrow. As they have said with a single shard universe is that actions have consequences. That said, you are right about the need for at least basic reforming of the terrain after mining on a planet. I am betting though that once we get into space, a lot more mining will be done on moons, asteroids and other airless places that we will not want to be vacationing. I wonder if we can mine gas giants. There are some amazing options that will not polute our planet. I also like the idea of grass and vegitation regrowth after mining operations.