Does The Doctor have the same feelings for people and things that he did before he regenerated? Does he have the same feelings for Sarah Jane that he did in the '70s?
Not necessarily, but with Rose, he certainly did. Meeting Sarah Jane again was deeply moving for him, I think. And what was interesting there was, he, in a sense, has gotten younger. That's The Doctor's eternal problem: he will always outlive his earthbound friends. And that's a great dramatic opportunity that you don't get in normal drama. You've got this character who's virtually immortal, certainly in terms of anyone from Earth, and how does that impact on those relationships? Even within a fantasy action/adventure scenario, you get to play these wonderful emotional beats. It's unlike anything else.