Sounds like you've got the build planned out quite well. Basically its just some stat allocation at this point and skill selection.
Halfling Outlaw Thief Operative
Str 8/Dex 18/Con 12/Int 10/Wis 11/Cha 14
Raise Dex, Con, Wis, Cha every 5 levels. The extra Con is to make up for the lower Halfling hit points at 1st level, as well help with the Operative's lowest save, Fortitude. At 1st, you'd have a respectable +2/+7/+3 saving throw line. Augmentations go to Dex, Cha, then Con.
Skills would be Athletics, Acrobatics, Bluff, Computers, Culture, Disguise, Perception (Thief), Sleight of Hand (Thief), Stealth, Profession: Video Personality.
This would let you take advantage of the charisma bonus while probably not stepping on an Envoy's diplomacy toes. I'm assuming the Envoy is going to be the Captain, so Computers would let you be a Science officer. You could alternatively swap Computer for Piloting or Engineering depending on what jobs others will be doing. With your charisma bonus and edge bonus, your aid another on Diplomacy should be pretty solid. If you need another skill beyond that, I'd swap Culture out probably, or bump Int at 5th level instead of Con.
I feel Bluff, Disguise and Computers are important to keep your Video Personality identity separate from your day to day identity. Its probably best not to video log with your real name and face if you're vlogging about stealing stuff. Good computer security is also going to be important if you don't want the authorities tracking you through infosphere postings.
Lastly, grab a small arms weapon, backup up operative melee weapon, and some light armor and you should be good to go.
Work with the player of the Envoy.
Even if you have some of the same skills, it is likely because of the Envoy Improvisations and Operative Tricks that they will be seen as bringing different things to the group. Perhaps you concentrate on Bluff while the Envoy does Intimidate (or vice versa).
Also, when building your Operative make sure you can fill more than one position in Starship Combat. It really helps with some of the more challenging combats if people can swap around some of the positions. In my experience, extra gunners can be especially effective.
What would it look like if I went, ICON/Thief?
Quick question, are we talking about actually being a thief? Like going around and stealing from people? Or merely like the Thief specialization of the Operative (which does gives you benefits for running illegal heists).
Its going to be potentially hard to take advantage of ICON bonuses if you need to keep your identity secret from the authorities. If you haven't already, I'd suggest talking about this combination with your GM so you are both on the same page, and understand how it would play out in game if you do this. If you're not actually planning on stealing and doing other illegal things then it shouldn't be a problem.
In any case, the build is basically identical. You'd get a bonus to culture to know about vlogging personalities instead of criminal enterprises. +1 to culture checks instead of +1 to sleight of hand. Bluff and Disguise jump up in importance, because you are a thief everyone can recognize with just a DC 20 culture check at level 5.
BretI's suggestion of talking with the Envoy's player is also a good one.
I think he means the Operative Specialization Thief.
Str 10 -2= 8
Dex 10 +2 +6 = 18
Con 10
Int 10
Wis 10
Cha 10 +2 +1 = 13
Still have 4 points to spend on attributes.
Their specialized skills are Perception and Sleight of Hand. These skills are automatically maxed (you don’t spend skill ranks to do it).
Exploit is Holographic Distraction.
Go ahead and pick your other skills.