Dan – You certainly have a haunted dream life!!
Lots of people have such nightmares, but maybe not so often. I have myself had many, but I have the habit of fighting back, and eventually get the b****** who are trying to kill me.
In every case where I have helped a person explore their nightmare it resolves into the memory of an incident or a serious of incidents that have terrorised the dreamer. And the fact that your father appears in one, even though it is not him in the end, suggests there was an incident that was behind your nightmares.
Sometimes such incidents are not meant to hurt you or frighten you, but because we are small and vulnerable we can be scared easily – just by being left alone.
Death in your nightmares can mean all the things you list. As a child, and even as an adult, we can feel cut to pieces and without any sure place in us where we can live without threat.
As you are becoming aware of dreaming such nightmares, it seems you could move beyond them. I can only suggest, in my absence, some things you might try. For instance you could try challenges the murderer(s) and push them to take of their disguises and to show where they come from, what past event(s) led you to such fears.
Try also fighting back. To enable this you need to realise that you are the creator of your dreams, as troubled as they seem. You can be anything you can imagine in your dreams. Or if that is difficult you can call on any figure to help you – a great warrior, a boxer, superman, in fact anyone you can feel would be of help.
If that sounds like a fantasy trip, ask yourself what are your dreams but a huge playground of fantastic images. Once you realise that you can gradually master your own fears. Perhaps reading
http://dreamhawk.com/dream-encyclopedia/the-magical-dream-machine/ will help.
Tony