I just noticed this, but I think I can answer part of that.
Bielefelder x Cuckoo Maran chicks you may be able to sex, because they will be pure for the barring gene. Males may have a larger head spot, and will almost certainly have more white in the barring as they grow their feathers. Females will probably have a smaller head spot or no head spot, and should have much less white in their feathers (still barred, but overall darker.)
Bielefelder male x Easter Egger female will not give autosexing or sex-linked chicks. (Exception for a few specific colors of Easter Egger female, but you probably won't be dealing with them.)
Bielefelder female x Easter Egger male MIGHT give sex-linked chicks, depending on the Easter Egger. He would need to not have barring. The Bielefelder mother will pass barring to her sons only, so if the father is not-barred, the daughters will also be not-barred. A white Easter Egger male would not work, because white barring does not show up well on a white bird
Cuckoo Marans hen can give sex-linked chicks with certain males, just like a Bielefelder hen can. Cuckoo Marans rooster will not produce sex-linked chicks with Easter Egger or Whiting True Blue hens.
And if you cross a blue-egger with a brown-egger you get a green-egger (blue shell with a layer of brown on the outside.) Some people call them Olive Eggers when the eggs are a dark green (because the brown layer is dark, like from a Marans parent.)
