Re: Regenerating The Doctor
"Fortunately most actors have as little knowledge of the gemre as the writers appear to have"
A lot of the writers, actors and production team all grew up with or have previous experience of DW.
Capaldi is a long term fan, as was Tennant, Moffat and Russel T Davies too. Phil Ford (Into the Dalek) wrote for Sarah Jane Adventures, and the Doctor Who Adventure Games. Gatiss (Sherwood) wrote Doctor Who short stories in the 90s too. Gareth Roberts (Caretaker) was writing Doctor Who novels in the 1990s.
Basically the fans have taken over the asylum. Gatiss is good with reworking and pastiche (if you note his involvement with H G Wells adaptations, Quatermass etc)
Since I mentioned actors. Tony Osoba (the other other member of the shuttle crew) has been in Doctor Who twice before, though for more screen time than he got this time around.)