So during the Cold War it ranged from extremely difficult to impossible for citizens of Eastern Bloc countries to emigrate to Western countries, even for family reunification. What about immigration between different Eastern Bloc countries? Say an East German women fell in love with a Soviet man and they wanted to marry; could they do that and one of them move to the other’s country? What about neutral countries; say the groom was Swedish, would his bride be allowed to join him in Sweden (or even him stay in the DDR)?
Yes they could. Before the collapse of the Berlin Wall I met a Czech woman living with her Yugoslav husband in Yugoslavia, as well as a Hungarian living in Belgrade, and a Yugoslav man in Czechoslavakia, both I think settled in and not just working.
More generally I think ethnicity and cultural affiliation was recognised as being separate to nationality and a legitimate connection, but was heavily managed and formalised through the State, although some minorities were targeted in different countries [and all bets were off when the fighting began after 1989]. And no one liked or tolerated the Romany and related groups or gave concessions to their cultural practices or cross-border connections.
My Dad, a Hungarian, went to work in East Germany as an engineer right out of college. This was in the 1950s. So it was definitely possible.
I just finished a novel set in Cold War Romania, and one of the points was that Romanians couldn’t go to any other country, even within the Eastern Bloc, and imports, even from Eastern Bloc countries like Russia and East Germany, were exotic and highly valued. But it also suggested that Romania was uniquely bad in that regard.
Thar was probably down to Ceausescu, who had his own ideas about running a Staliist state. Some members of the Soviet bloc were considered more Soviet than others.
I don’t know how hard immigration was for East Germans, but travelling inside the Eastern block was relatively easy. Germans have long been known for their fondness for travelling, in both East and West, and since East Germans couldn’t go to Italy or Spain like their Western brethren, many went to Southern locations like Hungary or Bulgaria for vacation, mostly by means of Trabbi/Wartburg, but there also were regular flights by Interflug to these holiday destinations. The Balaton and the Bulgarian Gold Coast had the same importance as the Mediterranean for West Germans.
Casual movement was relatively straightforward, either on buses, trains or even hitch-hiking.
Travelling with a Yugoslav passport, I was given easy transit as a fraternal socialist between countries in Eastern Europe even though Yug. was officially unaligned and not part of the Warsaw Pact. Was not hassled at a border crossing once, even though it was a second passport and my main passport was Australian - they just asked to see it and made sure the dates aligned and there was no doubling up.
I had a relative who married someone in Romania in the late 70s. Permission to leave for the US was not a problem at all.