Other than acting like Yorkshire was the back of beyond and Matt's accent I didn't really notice any... maybe I just wasn't paying attention.
Clara's Yorkshire accent kept slipping into a Lancashire one, but that wasn't a problem. I suspect the bad teeth joke was inserted for the US audience.
It's much like how they were always slamming Cardiff or Wales in the RTD years and on Torchwood. I'm sure much of that was lost on the US audience as well.
I'm sure a lot of it goes right over my head. But regional humor has a certain cadence where one person says something completely innocuous and the other responds with an apparent non sequitur. When I catch exchanges like that, I always start Googling. A recent example was "What's the opposite of bliss?" "Um ... Carlisle?" Google Earth showed me a town in northern England named Carlisle, so I got that someone was supposedly just insulted. What I don't get is why. Oh well, those crazy Brits! Folks in London and/or Cardiff don't like Carlisle for some reason. Let's file that away for future reference.
It's nothing in particular, Carlise is just perceived as a grim industrial northern town. You probably could have switched Carlisle for any number of other places (not all of them Northern) and the joke would still have worked. Slough, Scunthorpe, Milton Keynes etc.
Was really surprised by this episode. Had low hopes going into it as I did not think it would be a story that would appeal to me but then really loved it. Thought the blind daughter's acting was sublime. Only dud moment for me was the Doctor's 'ouch' when Diana Rigg fell off the stairs. Didn't think the Doctor would make a joke out of someone's death and felt out of character. But it was only a minor quibble.
Carlisle isn't that grim. It has some interesting ancient buildings and structures, although the civic centre building is pretty hideous. http://www.discovercarlisle.co.uk/discover-carlisle.aspx
Oh I'm sure it's a great place, a lot of places perceived as grim are actually quite wonderful, but as shorthand goes somewhere like Carlisle still evokes that grim oop North notion.
The longer he's around, the more Eleven seems to be getting a lot more comfortable with killing the bad guys. I'm not sure if that's intended to be "character development" or not, but it's something that I've noticed.
I think it's pretty arbitrary, and no different than any other relatively close major cities. I'm in Calgary, and Calgarians hate Edmonton. New York rags on New Jersey ALL the time. EVERYONE hates Toronto. And so forth. RTD is Welsh and simply ratcheted up the rivalry / playful antagonism between Wales and England like anyone would, albeit blunt to the point of confusion to us non-Brits. Doctor Who seems to have exorcised it with his departure, but since it's still shot there, traces of it will forever remain. Mark
You're right, it is generally out of character, but I interpreted that as meaning that the Doctor was so unbelievably revolted by what Mrs. Gillyflower (Diana Rigg's character) had done, that he could not muster any sympathy at all. For the Doctor to just say "ouch" indicates the extent of his utter contempt. After all, Mrs. Gillyflower admits to blinding Ada (her own daughter) in experiments to immunize herself from the toxin. The fact that Ada only discovered this when she overheard Mrs. Gillyflower indicates that Ada was probably blinded when she was too young to remember (i.e. when she was a toddler, or even an infant). Even the compassionate Doctor would have a hard time sympathizing with someone who blinded her own baby girl.
Last part sounds, intentionally or not, a bit vengeful, which I don't think was the case, but the indifference yes. The Doctor's always liked guns, pain and death.
...and it's really pretty rare to see an actual non-manipulated thoroughly-evil human baddie in this show, so when one does come up the doc isn't all broken up about them.