Considering ep 7 will be Naomi's ep, I doubt Effy would get the last shot, so no I think we can safely assume Effy shooting someone is not happening
Even if CK does happen and isn't about Freffy, it will still seem cheap. They will both be left overs from Freffy, but then it gives something for Katie to do and gets Cook to stop chasing everyone elses girls-so it could be a good idea.