To make it easy, the new language would probably be based on a language with most speakers, be it native or learned, and it would further push smaller languages aside. Say, it’s based off a germanic language. Germans or Dutch would learn it in a bit, but Slavic people might struggle.

Languages are tied to people and is a very important part of culture which is why fabricated languages would never even make it, but even if one made it, someone would have advantage in learning it and it’s a powerful tool.

No, respecting diversity is one of main EU values, this could only lead to discrimination.

I don’t think it’s everyone being ok, more like everyone complying because sometimes you have to.

And who refuse to explain even when asked?

Not sure what made them not work, but this makes sense.

Gaming. The only reason I went from Ubuntu to Windows.