Gallifrey certainly seems ravaged, but I've not seen any real evidence that it was ravaged by Daleks, as it were, not saying it couldn't have been, but I'm trying to think like a Dr Who writer, if they have one weakness, it is that they become too attached to their storylines and characters, and tend to not want to let them go, as it were

The problem is that the Doctor treats the story of the Time war like an Onion, there's layers that need to be peeled off, and the writers keep the whole thing deliberately vague, they've even openly admitted that this is because, when you are dealing with the entire space-time continuum, you can pretty much do anything you like, even if it directly contradicts things that have happened earlier.