Having toured in Europe and Britain, I can say that it is much easier to communicate in English in Denmark, Northern Germany and the Netherlands than it is in certain regions of England and Scotland. I couldn't understand a word in Newcastle or Glasgow. Most young French people have had at least seven years of English in School, but that always doesn't always mean they can speak it.
As far camping any where, I would advise against it as there is not a lot of vacant land. However there are lots of campgrounds, youth hostels and small hotels. As far as it getting dark, that is not a problem in Northern Europe in May June or July. So if a hostel or campground is full it isn't a problem riding another 30 km to the next one before dark.