Dutch and Deutsch are the same word that got pronounced differently over the time. No wonder they are so similar. If you would listen to old English (from "History of English" fantastic podcast), you will see how much it is similar to German, too.
From my experience in Europe, the bigger the country, the less people of it are inclined to know other <English> language. I had really hard time in Madrid and generally struggled in Italy. In German coutryside even the youngsters barely speak English, let alone the older generation. We will politely not mention France
On the other hand, in the Netherlands and Benilux as whole, Switzerland, English is like their second language. There were no problems in Austria. Younger generation in most of the places of Easter Europe has very good English and sometimes German as well.