Opportunist Rogue help

[BurgerKrieg]

For the campaign that I am planning on using this in, stats were rolled in order with no re-rolls. This is what I got:
Str:16
Dex: 17
Con: 16
Int: 11
Wis: 12
Cha: 16


I believe this is a decent progression chart. I am only including combat abilities that the build is focused on.

1: Rogue 1-->1d6 SA/Feat (Two-Weapon Fighting)
2: Rogue 2
3: Rogue 3-->2d6 SA/Feat (Craven)
4: Rogue 4-->Bonus Ability Point (Dex)
5: Rogue 5-->3d6 SA
6: Rogue 6-->Feat (Improved Unarmed Strike)
7: Rogue 7-->4d6 SA
8: Rogue 8-->Bonus Abilit Point (Dex)
9: Rogue 9-->5d6 SA/Feat (Snap Kick)
10: Rogue 10-->Opportunist
11: Rogue 10/Fighter 1-->Feat (Combat Reflexes)
12: Rogue 10/Fighter 2-->Feat (Savvy Rogue)/Feat (Improved Two-Weapon Fighting)/Bonus Ability Point (Dex)
13: Rogue 11/Fighter 2-->6d6 SA /Crippling Strike
14: Rogue 12/Fighter 2
15: Rogue 13/Fighter 2-->7d6 SA/Feat (Double Hit)
16: Open to Suggestion
17: "
18: "
19: "
20: "

I would like to know what might benefit the build I made the most from level 16 on. I'm having trouble finding things that actually benefit the build, aside from Sneak Attack.
Right now I'm thinking 3 levels in Guild Thief to give 2d6 SA and a bonus feat, which would probably be Weapon Finesse.

If you have any questions about why certain things are being taken, just ask.

[Safety Sword]

More of a suggestion than anything, but you might want to consider 2 Levels of ranger.

You lose 1d6 sneak attack, granted, but for that you'll pick up your BAB, hit points and get your TWF feats without using your actual feats.

[BurgerKrieg]

You're forgetting one thing, though. Opportunist is wanted ASAP, since that's the core of the build, so lvl 10 rogue is wanted right away. Plus a solid rogue would be a little more combat-effective than a rogue of two levels lower with two levels in ranger.

Another reason I didn't do that is because I've got no low requirement feats to take early on. There are only so many choices you can make at that point.

[BurgerKrieg]

Now that I think about it, 2 Ranger/4 Scout would allow me to take two extra feats, since TWF is granted by ranger, and scout gives a bonus feat. I could take swift hunter and swift ambusher to allow for extra versatility and cover the critical immunity weakness that precision damage has.