As far as the "failed fate, can you still get the item still?" question, from the NPC you start te quest, he does say something about needing to defeat the enemy to get this atma aether wielding the weapon. So for boss fates, it'd make sense you would not get an atma if it failed.

Also, I've never gotten anything from a failed fate except some experience and gold, boss or no boss.

So it could be assumed logically that you would have no probable chance of getting a drop from a failed fate. It'd be great if the devs could comment on this particular point, too. (Hint, hint.... )