On the second point, Johnson says:
...why do we get so worked up about these tiny things? People are tribal, and they often enjoy getting especially tribal about the tiniest things. Britons and Americans can both make passionate defences of driving on their respective sides of the road, or how many syllables "alumin(i)um" has, partly because, though the choice is arbitrary, it is defining: do you belong to the red team or the blue team? It seems to be in our nature to get worked up about these things.