Howdy! We spoke to the development team about your feedback on thief and they provided some commentary. The below is a compilation of responses to both the English and Japanese suggestions/feedback. Hopefully it will give you a better idea of what is planned for thief in the future.

With the large amount of job adjustment discussion going on we have A LOT of feedback to sort through, so while this might not answer every single thing being discussed at the moment, we will try our best to update when we can. Likewise, we will be making our rounds to other job related threads as well!

So, without further ado…

Instead of increasing the chances of successfully executing Steal and Despoil, can you actually add some attractive items to monsters for us to target?
By adding attractive items to monsters, we fear that it would be re-creating the scenario from the past regarding beastcoins (stealing and then hiding right after), making this pretty difficult to implement. If there were a good countermeasure for this it could work, but currently revamping or adding items to monsters is quite difficult.

Steal has no effect on notorious monsters…
That’s what Aura Steal is for! The effects stolen by Aura Steal are essentially the raw stats that the monster possesses.

Make Aura Steal its own ability.
We believe making Aura Steal a separate ability would be over-powered. If we did do this, it’s likely that its use on notorious monsters would be removed and it would have even less of an effect than it does now.

Add Aura Steal to Despoil as well.
Though we haven’t decided if it will be Aura Steal or not, we do have some rough plans for adding some kind of additional effect to Despoil.

Split up the recast timers for Steal and Despoil.
We are looking into separating the two. However, we are close to reaching a point where there are too many recast timers going on simultaneously, so this isn't something we can implement right away.

With ranger getting Treasure Hunter, dancer getting Triple Attack, and warrior having critical hits, I feel like all of thief’s big selling points have been taken away by other jobs.
While thieves possess superior stats for all of the above, we do understand your concerns. I apologize that I can’t go into detail about specific abilities, but we are planning to make adjustments so that thieves are really able to shine.

Add Subtle Blow to thief.
Due to the fact that normal attacks now increase the effects of Treasure Hunter, we chose to forgo the addition of Subtle Blow as a trade off.

I really hope that the new ability that complements Sneak Attack and Trick Attack is not on a shared recast timer with one of the two abilities.
Don’t worry, it will be separate!