I have to ask .... does anyone really care anymore who plays Who? I suspect only the sort of people who believe Klingon is a language and that William Shatner can act. 
Way back when I was a student nurse I had to work with a patient who at the time was convinced he was a klingon (and yes he was that much of a trekkie that he knew the language that had been created). All the staff had a hell of a time trying to get him to take his medication till I ended up buying a 'klingon language course' from the local bookshop. Worked wonders with him once I could tell him that if he didnt take his medication/calm down/stop threatening that person I would break his arm/leg/nose/neck and that he was an honourless dog.
While I did get in to trouble for 'fuelling his delusion' his psychiatrist had to admit that he'd become a lot easier to manage.
As for Robert Carlyle for Dr Who? I can just see a trainspotting moment: "Some c**t blew up this lasses planet and we're not leaving till we find out who it is!!!"