YUROP

Whereas Iceland wishes it wasn't an Island.

German alcohol taxes generally aren't bad, going to Poland or Czechia should mostly be about general shopping trips. The Luxembourg thing is absolutely true, but rather specific: In Germany you pay more tax per ml of alcohol the higher the ABV is and if you want to make your own liqueur you wan to start out with real high ABV and then dilute down, a litre of 96% is about 30 Euros in Germany, 20 in Luxembourg. Wouldn't be worth the trip for more pedestrian ABVs.

You can generally import as much as you want within the EU as long as it's for your own use, to not have to explain yourself keep the booze to under 10l per person.

German beer taxes are low, like 10ct per litre on average. Wine taxes are even lower because France exists, German vinyards do have a lobby and all they want is to make sure is that people don't get used to paying more than a fiver for a bottle or they might start buying import stuff.