So here you are a level 20 and you just maxed out your first boss dropped power hand cannon. She kept you alive and she did her job well and it was such a sweet moment so long ago in 2014. But you just liberated a Thorn and it's 2015 and you're in neck deep in Destiny. That Thorn is your new wingman. Black shiny and deadly. Adventure after adventure you just plow through Hive knights like a hot knife going through butter. Alas you decide I really want to try out being an Awoken Warlock. Off to the character creator you go. And hopefully a hour later you're an Awoken hero ready to get... Curb stomped by level 2 Fallen all over again with your City issued ordnance. Whatttt? You look at your character screen and theres that gleaming Exo Titan who drank Cabal blood and stomped sixty bosses into cat chow just waving atcha. While your level 3 Awoken looks sheepishly lame and sorry for it. But wait! Did Bungie give me the ability to swap weapons from other characters? Can I trade with a friend at a higher level and give them a gun from my arsenal so they can meet my Gomer character later on and hand it off back to me? Oh, that would save so much time. and I'm reunited with an old friend...Who Bungie stripped back down to level 3 and she and I have to work again to get those perks open. Well ? Will you trade guns with your lower tiered characters?
Since Bungie's been really big on "investment", I think item trading (especially Exotics) will be limited between Guardians. If it is made possible, aside from items being bound to an account, items could also have level/focus/time/etc restrictions so twinks aren't ridiculous.