"Trading has the potential to wreck the reward loop, just like the auction house did". Absolutely 100% agree - if I could trade my clan mates, who have been away for a few weeks, some of my awesome gear I found like my 2nd Kridershot that is idling on a twink, it would be awesome for them... but it would also make it a bit more pointless for them to play and farm for it. Plus, it just doesn't feel great if you jump into the game, get all awesome gear right from the start and... that's it. Just like the AH. And of course we're not even talking about the potential exploitation through "trading clans" (your 30 day thing does nothing, you could easily join a D2JSP trading clan or whatever and just play GRs with your friends over friends list).
I always asked for trading in the game since AH left and Smart loot cames out, but you got a point there ... I got a few items that are also idling there and could get some worth if trading was possible...
but yea, we could go for another way, and make a loot class selection. Iknow smart loot is not 100% but it would be awesome if we could choose what class we would like to be selected by smart loot (kinda the same functionality that exists in WoW).
Since we can earn shards with one character and spend all of them with another one, I guess this would not kill the game as trading system would do.