Can I play Black Ops 2 without having played the previous games ?

yeah you can, but there are somethings, minor things, that you wont pick up on

you can, but one does not simply play black ops 2 without playing the previous games, it just wont be the same.

You can, in terms of your data, but if you are talking about the campaign, you would need to know some things, such as: the relationship of woods and mason. Now, If you are talking about the multiplayer or zombies, in regards to experience, you can develop experience by diving straight into the multiplayer action and progress, but if you want to be good I advise playing previous COD games.

I suggest this b/c there are tactics, that only experienced players know: you would have to know how to deal with campers/ unruly teamates, rape train zombies, how AI works, how to quickscope, etc. These tactics would separate you from the noobs.

Black ops 2 was my first fps for the ps3 and I didn't need anything to play it. So you can do it too.

well mw games doesnt matter but if you dont play black ops its not the same

Of course

Yes, it's allowed.

I believe so, yes you can:)