"[N]o true Christian "just warrior" will ever celebrate his having killed, or rejoice in it, or boast of it. Nor will that warrior's society. Killing is always an evil, always a source of sorrow, always to be regretted."

I totally, totally agree . . . except for the proposition that killing is always an evil.  Killing is at times the moral thing to do.  But even then, as you say, killing is to be regretted and is always a source of sorrow.