Clara, you got a lot of hits on that last one alright. XD Politics, definitely: The Third Doctor dealing with the alien alliance both times, Harry's remark about a British Prime minister in Arc in Space, etc, though I was never a huge fan of incorporating such things.
The 'morality' of the show was more or less lost when the 'Doctor' was lost. From Hartnell to Troughton to Baker, they all had presence and they made the rules loud as they went. Tennant could have done that except that the format of the series had been changed to a drama where such things don't matter so much. It's more about the explosions, high speed, Tardis in flame, that sort of thing.
I mean "Bad Wolf" was New Who trying to be cool for the kids by putting graffiti over everything.
Eccleston was the Doc's midlife crisis? XD good one. I have nothing against the actor, he was solid, he just was not the Doctor. He could've played a million other roles, but he was not the Doctor. He reminded me way too much of Bundy.
It's also funny to note, ignoring the Seventh Doctor (Maybe he was exaggerating like the Third), that the ninth was 900 years old, then tenth was 901, and the eleventh was 907. He's definitely suffering a midlife something.
Si-Fy and Fantasy, that is where my heart lies. To Doctor Who and its 18 years of brilliance, still waiting on the 50 yr anniversary!