Continuity mistake: When Colonel Blue informs the team that radiation levels are getting dangerously high as they head for the Dalek's trionic power cells, the team's location inside the Dalek, shown on a computer screen, changes between shots. (00:25:16)
Continuity mistake: During Clara's first conversation with Danny, the folders in her hands are unmarked in close-ups, but have labels on them in wide shots. In addition, the folders and newspaper she's holding keep changing position between shots. (00:07:30 - 00:08:26)
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.