All your suggestions seem geared toward the multiplayer, which I never play anymore.
I do have some ideas for single player though:
Include different militaries: MW2 basically ended with WW3 opening up, so I imagine more parties are involved than Russia, the US, and some isolated SAS chaps. I want to see levels as the Israelis, Australians, Canadians (No way they're not integral in a war between the US and Russia), or levels against Russian allies. The same old RAVs are getting old.
I also want to be on the other end of the Guerrilla Warfare combat, as in playing as American civilians fighting remaining Russian forces with their own household weapons and scavenged equipment.
A comprehensible narrative and thought out script would also be nice, but we can only ask so much from big budget US developers these days.