I can't help but feel that trading would have a very similar effect on loot that the auction house had on items in Diablo 3. For those of you who never played Diablo 3, it had a system somewhat similar to Destiny with some guaranteed drops for beating certain bosses (like getting the Strangers gun at the end of the story in Destiny). Having players be able to trade (or in that case, auction) would break the game for me. I would stop playing the strikes as much and I would do my best to find someone who would take some piece of crap item and give me something that is more in demand so I can keep trading until I get that gun that I want. The number of Guardians playing strikes and doing patrols would fall dramatically and we would all be in the forums with thousands of posts asking for trades and complaining about it. The auction house was removed from Diablo and in my option its a better game for it. I would hate to have a system implemented that did more harm than good, sometimes what we personally want is bad for everyone around us. That's just my two pennies.