The biggest thing I'd change is either get rid of those damn Riot Shields or make a perk so you can either rip it out of their hands or break the damn thing with your Melee knife. There is no way those things are that resistant to everything.
on a different note, I personally think Cold-Blooded is a waste of time. If I have a default scope, your screwed. Even with a thermal, you can still be seen...same with like the Predetor Missile, Chopper Gunner and AC-130. You can still be seen by them. As for the other killstreaks, the solution is either shoot them down, or stay out of their sight.
Fear the Fallen