^^yes 6you can rank up off line i am 4th prestige on split screen and 5th on xbox live, but your unlocks do not carry over from xbox live you have to do them seperatly
edit: i believe you can check the "xbox live unlocks" toggle to on, however this only pulls your live unlocks into the split screen, and any xp gained/challenges unlocked/etc wont count towards your live account. (im 85% on this).
Yes, online and offline.
No, you can play splitscreen spec ops and offline multiplayer though
on split screen, no, on live, yes
yes
yes
you cant
Campaign screen.
You can't
Unfortunately no, you can't play multiplayer on Call of Duty Modern Warfare 1 or on Call of Duty Modern Warfare 2 on the same screen. But on Call of Duty Modern Warfare 3 and Call of Duty Modern Warfare Black Ops you can play multiplayer on the same screen. There is an new Call of Duty Black Ops 2 coming out soon though, so I expect that to also have that feature, since its newer.
you go to the menu screen, jk who knows
You can not play split screen on multiplayer. It also left me confused
You can only do split screen if the person you are playing with is with you.