Normals come in lots of different colors. I have 2 normals and one possible het and NONE of them look anything alike, so you should be able to find a darker normal but you most likely won't find one that is nearly black.
I believe some breeders cut the eggs to make sure that nothing goes wrong. I believe it is possible for babies to drowned in the eggs. I think most will cut after the first one pips though, not sure as I can't speak for everyone and this is just my understanding.
I agree, it also sounds like baby behavior too. I had a few that loved to snap at me when I opened their tubs when they were little, but have since calmed down.