New Steal: Level 1-30

Tay's build seems to imply that you're maxing Nimble Body. Which would leave you with Lv18 or Lv10 Dark Sight. Depending if you're a sindit. That'd cause you to use 2nd job SP to max a 1st job skill, a total waste. And then suggesting to use 3rd job SP to max a 2nd job skill? The build becomes too absurd by then.

Why not go as ->

 Spoiler

1st Job
Nimble Body - 9 or 10
Keen Eyes - 8
Disorder - 3
Dark Sight - 20
Double Stab - 20 or 1 or 0 = Lucky Seven - 20 or 1 or 0
You're choice on which you want to max. Double Stab or Lucky Seven. If you want to max one, and have Lv1 of the other, you're going to have Lv9 Nimble Body. If you leave one at Lv0, you'll have Lv10 Nimble Body. I don't see the point in a bandit trying to get as much accuracy and avoid as possible.

2nd job
Dagger Mastery - 20
Endure - 20
Dagger Booster - 20
Haste - 20
Steal - 11
Savage Blow - 30
Lv11 Steal gives you a three second stun, and hits three monsters. The previous posts already showed Savage Blow still being the better attack, so you're not losing out on much at all. Steal will still serve the purpose you want it for. For taking a monster's items, or stunning. Lv11 is good enough. No need to go wasting 3rd job SP on it.

3rd job
Shield Mastery - 0
Chakra - 30
Assaulter - 30
Pickpocket - 11
Band of Thieves - 30
Meso Guard - 20
Meso Explosion - 30
I don't think Pickpocket is very useful, but others think Chakra isn't very useful. I'd go with Chakra over Pickpocket. But I guess you can leave it as interchangeable.

If you must have a high leveled Steal, then sacrifice Lv21 Chakra or Lv11 Pickpocket. I don't think it's worth sacrificing either for a higher level of Steal.
Not maxing Dark Sight at 1st job is what throws everything else off.