Wow. So many questions. Many of them directed at Germany rather than Europe, but I'll try and do my best.
Run on sentences don't bother me because some German writers have a tendency to overindulge in that respect. Ever tried reading Thomas Mann? That man could fill an entire page with just two sentences, one on a good day.
The answer for Europe: Coexisting with so many neighbors that all speak different languages requires a certain level of foreign language skills. As a rule of thumb, the more exotic your native language is the more you will depend on English as a backup. That's why the Dutch and Skandinavians tend to be so good at it (well, being in the same language family probably helps too).
Here in Germany kids go to one of three types of school depending on their skills and ambitions. One offers English, the other has complusory English classes and offers a second foreign language on a voluntary basis and the third type has compulsory English plus one other language (usually French or Latin) and allows you to later add a third foreign language. So 2/3 Germans among the younger generation have had compulsory English classes for at least a few years. Only those who graduate from the third type of school are allowed into university where some lectures might be given in English and a lot of the text books are in English. My parents and brother and sister were all relatively bad at English back at school but had to brush up on their skills once they went through university. Often there isn't even a German word for some of the terminology used in cutting edge research.
But don't let that fool you. There is a reason I can still make a living as a translator for English and Spanish. What I just described are the offical standards and how things are on paper. But there are a lot of people who do struggle with English. Only the other day I witnessed a Chinese couple at the post office trying to get a letter mailed to Hongkong. The lady at the counter just gave them a blank stare and told them in German that she spoke no English. She wasn't apologetic about it either, just stating it as a matter of fact in a sucks-to-be-you kind of way. As somebody working with customers in a city filled with tourists (I live in Heidelberg, we have had tourists here ever since the invention of tourism!), that was suprising. Oh well, after all, we too are only human /rant
Short answer: Most will speak some English, enough to get by and among the younger generation, mainly college students, proficiency is almost a status symbol (in the "I don't own a tv but watch the cool series online in English as soon as they come out" or even "I refuse to watch a movie if it isn't in the original English version"-hipster style)
Oh. That's enough material for a few pages, volumes even. Short answer: There are still visible differences but they are slowly getting less and less important. It will take a lot of time. People born on the day of reunification are now in their early twenties. Let's see how they develop. I think the reunification was badly managed and rushed into (after all, there were elections to be won) and I still have to pay extra taxes (the so called Solidaritätszuschlag or solidarity tax for the reconstruction of the East) for those damn East Germans twenty years later!
I have only been to Sweden as a tourist. Apparently there is something the Swedes call Bullerby Syndrome: the idealization of Sweden by Germans. So I might be biased.
Let's just say there are definitely worse places to live, but of course they too have their share of problems. However, if I had to leave the country and pick a new home based solely on quality of living, I would pick Sweden or Norway. Icelanders and Danes are usually way up there on the list of the world's happiest nations. These tend to be open, welcoming, solidarious and tolerant societies. Add to that a high standard of living and gorgeous landscape and you've got yourself a nice place to live. Remember there was a special design prize awarded for the creation of Norway?/Douglas Adams reference
Thank your Mum or girlfriend or whoever makes you eat healthy!