I would say don't go to former East Germany, including Berlin. Bayern and Baden Württemberg are one of the most peaceful and safe regions in whole Europe, though a bit conservative. I absolute love leaving there, although I'm a foreigner which still can't speak proper German or Schwäbisch.
Though, as a white man, my experience about behaviour of natives might lack first hand perspective of how it looks for black people.
Including Berlin, seriously? I'm tempted to agree with you on the rest of eastern Germany, at least rural regions. But Berlin is more of a multicultural, open-minded island.
Southern Germans however, as you say, tend to be quite conservative. I'm glad for you that you like it here. But as I see it, the most important reason keeping the south from being as unfriendly to foreigners as the east, is its relative economic success and therefore less need for scapegoats.
Though, as a white man, my experience about behaviour of natives might lack first hand perspective of how it looks for black people.