Even UK vs Netherlands is a significant difference in how things work in business deals and that's just a 45 min flight. Unspoken expectations are different on how the other side is supposed to behave.
Denmark is a bit better, maybe because they drink more ? Dunno.
Not really, if you get a "yes" in the Netherlands, Nordics, Germany or Poland it does mean, simply, yes.
The consequence of which is that actually getting a "yes" takes a lot of work.
I don't dare speak for other countries, no experience there.
Maybe the overall consumption is higher in Germany, but in Denmark everyone is out drinking much more than in Germany.
Where do you get that notion? My education (and some googling to refresh my memory) has Norwegian, Swedish and Danish classed as "North Germanic" according to comparative linguistics. That is one subset of the West Germanic languages which most of northern Europe speaks.