Ref the Doctor being a dick - I pretty much agree with everything you said there. one thing that struck me a week or two ago was how often the Doctor apologies; he says "sorry" in almost every single episode. And Tennant somehow manages to make this seem utterly real, whatever the context. Whether it's a "I wish I didn't have to do this but I'm going to anyway", or a "I really wish I hadn't done that" or a "I sympathise" or whatever. Somehow, he takes this flippant arrogant egotistical dick and creates instant depth to the character, simply by being convincing when he says "sorry". I don't recall any of the earlier Doctors apologising half as much.