I live in Germany. All people here have english at school. But this does not necessary mean they can read/speak english. Actually my feeling is that most people here are not comfortable with english: my guess is 95% of all handcrafters do not speak it.
My father in law is a doctor and has a good education. He does not speak english because he never uses it. He is a tech-fan and has always the latest iphone. But he never installs software which is not translated.
the situation in germany might differ to the situation in for example finland. In finland movies are not always translated. Many of them are in the cinemas with the english original language and subtitles. Finnish people usually have an excellent english.
In germany there is not a single movie which is not translated. Therefore most people do not need the english language and forget it.
That being said, I even know some tech people with a very bad english.
And if you look at my post, you'll find many grammar / spelling errors. I can read the lord of the rings in the original. OK, all of my software is in english, but hey.
So my recommendation is to look at each country you want to publish and decide for each one.
Germany is a must.
France is even more a must - they are picky abou their language and they even translated technical names. In germany most people understand "hard drive" or "usb stick" without a problem, I head this is different in france.
The scandinavians all speak a good english.
Italy and Spain is like France/Germany.