None of those are EV specific, they are just reasons the car market in Europe would be small. Rather than speculate about all the causes I thought I would just look it up:
In 2013, there were 12 million¹ vehicles registered in the EU out of 733 million people. And in the U.S. there were 15 million² sales out of 315 million people.
So it looks like Europe is buying cars at about a third the rate of Americans.
¹ http://www.nytimes.com/2014/01/17/business/international/car...