I don’t know much about the EU system. Does an Italian, say, need a permit to move to Poland? I thought one of the EU advantages was visa-free travel among member states?
No, a citizen of any EU country can travel, live and work in Poland.
No, a citizen of any EU country can travel, live and work in Poland.
If he stays longer than 3 months he does need to register. He can apply for residency, but that would just be to give the right to vote at the local ie mayor etc elections