Anybody can buy those? I thing the discrepancy in firework laws between the US and the EU are very strange
The gun laws are too, but in the other direction.
Austria, Switzerland, France and Belgium has very liberal firework laws. Sweden has had pretty liberal laws, but they banned firecrackers in 2001 and now they banned the 4" and 3" mortars, even if you can still buy pretty big rockets and, of course, build your own mortars.