In French, it would be better to use "Achetez" (third person plural, considerate the polite form) instead of the much more informal "Achète".
Also, I would suggest to make circle of stars broader, broad enough to include the slogan in its entirety. There is room left around each flag for that, and fr the few ones where it won't be enough (like the last one) it won't be enough, it should be ok to make the font a tad smaller/play with spacing on that one flag.
well... maybe we wouldn't. the EU membership will make it harder to steal both for the greens and for petya+whoever is next. they are all capable of promising the EU membership forever until the end of times.
I was about to indulge in pedantry on the basis that some of the languages mentioned are from countries that aren't EU members. But TIL that the EU flag was originally the European flag (which was later adopted by the EU), so I'll allow it.
The Lithuanian spelling translates back to English as more like "Buy like a european". I think a more accurate translation would be "Pirk iš Europos" or "Pirk Europietiškas." The second suggested option is a more direct translation of Buy European.
And “Osta Eurooplast” means buy European person. The correct way to write that should be “Osta eurooplast” - that way it would be at least grammarly correct.
“Osta Euroopa toodet”, “Osta Euroopa tooteid” or “Osta Euroopa toodangut” would be correct way to in Estonian.