Corrected entry: In episode 3, there are no crowds outside the Louvre when the Doctor runs up to it (just two gendarmes). It seems unusually quiet for the what the Doctor described earlier in this story as "the most famous art gallery in the universe"...
Corrected entry: 'City of Death' is set very definitely in Paris in 1979. There's even location filming in Paris to establish this (it was the first time ever a Doctor Who story was filmed outside the UK). Yet EVERYONE in this story speaks English. Even the TV News report in the cafe (reporting that the Mona Lisa had been stolen) was in English. Couldn't the film makers find anyone in Paris who spoke French? After all there's about two million people to choose from.
Correction: The Doctor has the ability to understand any language (not all aliens speak English), a timelord ability that is extended to anyone who travels with him. Thus, Romana would have the same ability and other companions who are not from Galifrey would be able to share it. This fact is established by the Doctor himself in a later story.
Correction: We only see a close-up of one entrance, not a wide-shot. And given that the prize of the Louvre collection has just been stolen, it's likely that the Louvre is closed to tourists.