no you can not because treyarch likes to make good games bad.
yes
Yes
Yes you can!
yes
Yes.
Yes
unfortunately it doesnt The PS3 and Xbox 360 do have online split screen
Call of Duty Black Ops is four player split-screen, and 2 can play split-screen online.
There is 2 things about this. You get an offline (Splitscreen) exp system. and an Online exp system. which means if you play online. you gain exp normally. However if you start a split screen you get a new exp and start back at level 0. You get exp on split screen. However it doesn't add to your online profile. So your online profile could be level 60 where your offline (Split screen) profile could be level 30. Hope you understand and hope this helps you.
Both.
yes you can
No only on campaign is split screen
yes
WEEB