I'm so sorry to hear that two of your girls were killed.
They were very pretty. I hope you can get some new ones hatched.
I don't really care too much about the chickens being pure bred. I care more about if *I* think they're pretty and if they lay well, and lay pretty, multi colored eggs. I have 8 hens and 1 cockerel. None of the chickens lay exactly the same colored egg, so it makes for a fun egg carton. I've had a couple people mention my BCM are really good looking and possibly show quality, but frankly, I'm scared to put them in a show and have them out of my immediate control.
It should not take longer for the EE's to hatch. I hatch EE's all the time and they are right along with my others, I do have one EE that I recognize by the color of her egg(happens to be a beautiful blue) Her eggs never hatch. They develop but never pip. Makes me sick but I keep trying. If your eggs look the same could they all have come from the same hen? You may have the problem I have whatever that is. The shell seems no different and the air pocket develops normally.