I don't have the definite information you're looking for, as I'm not near the National Archives (if you can get there, you'll likely find everything you want and more, but plan ahead, and request what you want at least a week beforehand!), however I can offer a few bits and bobs.

Newspaper culture: Yes, very strong! There were many newspapers, throughout British North America. PEI had 7 or 8 immediately apparent ones when I was looking, and Canada had a much larger population. There would have been different ones for French Canada and English Canada, as well as Protestant or Catholic papers. I don't have the names of the various papers with me, but you can definitely find them in the archives (probably even on the website).

As for the difference between Upper and Lower? Well, they were smushed together to try to stop the threat of fighting, but it wasn't a great compromise. It was rather similar to the tensions we have between English and French Canada that we have now, actually, and was part of the reasoning behind the creation of Canada; worries about fights breaking out between the two led to the smushing together, which really didn't work, so un-smushing them but keeping unified as a country was the next attempt. So, definitely not universal, except on paper.

I can't give you much more than that, as I say. However, I can try to point you to someone who would know, depending on where you are asking from!