Split screen is unlikely as it requires having multiple versions of the game running, and either multiple accounts logged in, something that consoles struggle with, or 2 characters active from one account and as skill points and weapons are tradable between characters it would get abused very quickly
English
-
Well every game that can have weapons traded gets abused who really cares about that lol they patch one thing we find another way.
-
When the game launches you'll only be able to trade between your own characters on your account. Bungie are leaving out trading between players until they can work out how to monitor and control it so its not abused or breaks the games economy