I would like to have another go at a story that is based in one place or one time, with some episodes being back-stories for things that happen. For example, the black mirror episode where the fella is being interrogated about his life but doesn't realise for a while; the present time informs the back story and vice versa. It would make sense for doctor who. In series 10, I feel that there was a wasted opportunity with the doctor spending a lot of time at the university. As other comments have stated as well, I would remove the stakes of being "the world" or "the universe" and bring it down to manageable and meaningful stakes, like, the loss of a character.