Vincent and the Doctor - S5-E10
[Van Gogh overhears conversation.]
The Doctor: But I just wondered, between you and me, in a hundred words, where do you think Van Gogh rates in the history of art?
Dr. Black, museum curator: Well, um, big question. But, to me, Van Gogh is the finest painter of them all. Certainly the most popular, great painter of all time. The most beloved. His command of color the most magnificent. He transformed the pain of his tormented life into ecstatic beauty. Pain is easy to portray, but to use your passion and pain to portray the ecstasy and joy and magnificence of our world, no one had ever done it before. Perhaps no one ever will again. To my mind, that strange, wild man who roamed the fields of Provence was not only the world's greatest artist, but also one of the greatest men who ever lived.
Vincent and the Doctor - S5-E10
Amy: So you were right. No new paintings. We didn't make a difference at all.
The Doctor: I wouldn't say that. The way I see it, every life is a pile of good things and bad things. Hey. The good things don't always soften the bad things, but vice versa, the bad things don't necessarily spoil the good things or make them unimportant. And we definitely added to his pile of good things.
Chosen answer: 1) When Stephen Moffat took over he ignored a lot of what had been developed before (there is not in-universe answer). 2) It would have killed Rose, so the Doctor absorbed the energy. His body regenerated before the energy could do a significant amount of damage that would prevent regeneration.