The Doctor Who timeline has hardly been the most consistent anyway. Have some faith in Mr Moffat, he clearly knows what he's doing.
I7m not so clear on that. He might know what he is doing, and have some great things in the works, but I wouldn't say it was "clear" based on Series 5. I holding judgment until after I see how the hanging story threads for Series 5 get cleared up. It could all turn out to be some brilliant long term stroy arc, or it could turn into Trail of a Time Lord.
My corcen with the "Time Can be Rewritten" thing is that it eliminates one the key reasons why the Doctor "allowed" bad things to stay "happened." Thigs like the Blinovitch Limitation Effect, The Web of Time/Fixed Points in History, the Timelords, and Thre Reapers, all helped to explain why couldn't always change history or go back and try again to get things right.