For me in practice going to UK meant that I had to show my passport on the border, while nobody cares when I travel across Schengen. I don't know what would hap

For me in practice going to UK meant that I had to show my passport on the border, while nobody cares when I travel across Schengen. I don't know what would happen if they tried to hold me. The biggest reason why Schengen Area is not equivalent with EU is that there are countries that are not part of EU, but are part of Schengen - Switzerland and Norway as well as there are countries that are part of EU but not yet part of Schengen like Bulgaria and Romania. I never was in Bulgaria and Romania, so I can't speak of practicalities. And yes, Schengen countries have common visa policy.