Sinfonian:
To pick an LDoN chest:
-Make a Pick Lock skill hotkey.
-Target the chest and stand right next to it.
-Click on the Pick Lock hotkey to attempt to pick the chest.
-If successful, click Open to make the chest available for looting.
Unlike with doors, the hotkey is the thing to use on chests.
As for the aggro bug, I used to have issues with that, too, even when I didn't have aggro from anything. I think it may have something to do with actions taken while getting the box open (i.e. if a trap gets set off or you fail to pick the lock on the first try, then you may get stuck on some sort of mock hate list and won't be able to open the box due to "aggro"). That's mere conjecture, though.
To fix this, just hit your Fading Memories hotkey. FM has never failed to enable me to loot a chest when I keep getting a "D00d. You're liek totally on something's hate list" message. If you're OOM or don't have the ability, then camping and returning works as well.
I hope that helps. :)
On Topic:
And yes, I agree that LDoN chest loot is usually subpar. STA augs are a treat to find in a box though, and being able to have a one time barbarian morph is always fun. I do agree that they're often not worth the risk, though.