Can I just say you mapped this out beautifully?
I feel like UK soaps have fallen into the same curse that US soaps have, where sensationalism/shock-factor trumps character arc. I think the excessive murdering and doom/gloom take away from reality. Honestly, I am stunned that a writer hasn't dropped a line in there with one of the characters mentioning dreading X-Mas to NYE time, as there's always a murder.
I've said this countless times, but EE lost me when they killed Lucy in a stupid, pointless murder, and made it worse by making Bobby the killer. And then seeing the clips from earlier this year with Martin being killed off was further disheartening. I just never think it is smart to kill off core characters unless it will ricochet and impact the rest of the family for years to come.