So the idea here is pretty simply, an envoy that maximizes Move + Standard or 2 x Move (Haste) + Standard. A simple example of a cadence would be Improved Get Em as a move for +2 to hit followed by clever attack (flatfooted to you, flat footed to the entire party if you make the bluff check (for a total of +4 to hit) followed up with an attack with a sniper rifle.
The simplest cadence is Get Em (move) plus a standard attack. Building to optimize cadence can get tricky. Let's look at a character that will be played from level 1 to 14, with the caveat that the later levels are iffy, the game might not last that long.
Themeless Halfling
Halfling Luck
Halflings receive a +1 racial bonus to all saving throws. This bonus increases to +3 against fear effects.
Keen Senses
Halflings receive a +2 racial bonus to Perception skill checks.
Sneaky
Halflings receive a +2 racial bonus to Stealth checks. In addition, halflings reduce the penalty for using Stealth while moving by 5, and reduce the Stealth check penalty for sniping by 10.
Sure-Footed
Halflings receive a +2 racial bonus to Acrobatics and Athletics skill checks.
Stats
Str 8, Con 10, Dex 16, Int 11, Wis 10, Cha 18Initial Skills: Diplomacy, Bluff, Intimidate, Sense Motive, Perception, Stealth, Culture, Spread [start putting one point in class skills).
Themeless class skill: Survival
(Why themeless? So you can put one point into multiple class skills, then hit it with the themeless once a day +2 bonus to be vaguely competent).
A quick note on skills: If you plan to play a starship captain modify this build By replacing Stealth, Culture and spread with Piloting, Engineering and Computers. Pickup Stealth at level 5 and Culture at level 10. You can flip from Themeless to Spacefarer to give some shot with the missing skills, though the floating +2 from themeless might do you more good. Also flip the starting expertise skill for Diplomacy and pickup slick operator at level 3 pushing the intimidate talents back. It's not absolutely combat optimal, but will help with the substantial non-combat tasks you're facing.
1. Inspiring Boost (Restores up to 6SP. Useful in getting the party to second level).
Initial Expertise Die: Intimidate.
Level 1 Feat: Sniper Weapons
Spread: Acrobatics (1)
2. Get Em.
This sets up the most simple cadence. Get Em and either shoot or heal as a standard.
Spread: Pilot (1)
3. Menacing Gaze (The need to have expertise dice limits this choice to either Sense Motive or your first expertise choice). This means that you can use
Spread: Engineering (1)
Feat: Versatile Weapons Specializaiton
4. Dispiriting Taunt (Why not clever feint, because summoned creatures and microbot swarms also inflict flat footed).
Spread: Disguise (1)
5. Second Expertise Skill: Diplomacy
Improve Base Stat Array, Str 8, Con 12, Dex 18 (20), Int 12, Wis 10, Cha 19 (23).
Add Skill: Computer (or Pilot)
Spread: Athletics (1)
Feat: Improved Initiative
6. Improved Get Em. This opens the option to use Get Em either as a move action or as part of a attack.
Spread: Survival (1)
7. Rattling Presence
Feat: Deadly Aim (Move, Get Em, Haste: Aim, Attack with Sniper Rifle at range with Deadly Aim).
Spread: Slight of Hand (1)
8. Quick Dispiriting Taunt. Haste circuits are level 8. This means that you can now, Taunt, Get Em and Menacing Gaze, followed up by Taunt, Get Em and Shoot.
Spread: Your out of spread skills (except Profession). Just put everything into Disguise from here on out.
9. New Expertise: Bluff.
Feat: Spell Breaker
10. Hurry
Improve Stat Array, Str 8, Con 12, Dex 20 (22), Int 14, Wis 12, Cha 20 (24).
Skills: Max Disguise (or Computer or Pilot).
11. Slick Operator
Feat: Enhanced Resistance (Kinetic or Fire, unless campaign specific).
12. Improved Hurry. So you can now:
Ship a move
Taunt (haste)
Get Em (attack)
or
Taunt (Move)
Get Em (Haste)
Ship a Standard with a RP.
13. New Expertise Disguise or Engineering
Feat: Veiled Threat or Greater Fortitude
14. Situational Awareness. Hold an action, then spend a resolve to shift the trigger and another to shift a standard action to an ally that needs it. I'm not really a fan of what it does to your place in the combat order.