Way to bottom line it, Bro!
I respect that argument but you are opening up a whole can of worms if you exclude stressing the innocence of the humanity.. and just argue the humanity. It'll get very sticky very fast, and many a good Christian will have issues with the logical conclusion of such an argument.
For example, if all we are stressing is every humans right to life, then we should be out marching in the streets to end capital punishment and to STOP THE WAR!! and a host of other nonsense.
The only issue which really gives me pause as an "rational exceptionalist" (cough cough) is the innocence of the child.
One of the only ways around the absolutist "evry human is precious" moral dilema is to say that it is immoral to take the life of an "innocent".
Under this doctrine then, The guilty can and should be punished by society. The innocent should be protected. Killing in war is unfortunate, for example, but allowed.
Innocents shouldn't die in war, for example, but we know it happens.
If one takes the absolute "every human is precious" view, (and I know a few Liberal Christians, yes there are some, as well as Peace Church members who do indeed takes this approach) then we really have some moral issues to think about on a host of issues....