Isn't this basically what people have been saying? Apart from the Kills v DBNO, nothing new here. Holistic ELO rewards (which they do give out, just not significant enough), Unbalanced OPs, and more charms/achievements.
I disagree with you on Kills v DBNO, sounds like you want to save your KD. I would be just as happy if my friend sweeps in and finishes him off so long as the enemies are one man short. Unlike all-out games like BF where you can kill 50 in a match, your KD is not going to change after 3-4 seasons of playing regularly. I doubt people who finish downed enemies are aiming for the overall KD and not just shooting anything on sight (which is what you want anyway).