Every single level on little big plant is 4 player you just have to connect another controller to get more players.
In one of "The Canyons" levels In littlebigplanet 1
On DLC's
there a total of 25 story levels
no you need to purchase the new game
From the African levels
yes you can...
NO
There used to be a way, by hearting it, but it's been patched
online mode
There is not one
Because you can make your own levels
You use the Tools Bag