Grenades and missiles are messy and excessive, your aim and careful planning are what make missions happen.
Aim
When you assess (whether or not you succeed) your next attack against that target deals an additional 1d8 damage.
Skermisher
+2 speed (1/Round) Action: move for free. You can do so as a Reaction when an enemy moves adjacent or an attack misses you.
Keen Eye
You have Advantage on Perception, Examination and Insight checks, against targets you can already sense.
Weak Points
When you crit, double the damage from Aim.
Subclass
Choose an Operative Subclass.
On the Move
When you move, gain 1 Defense per space moved (1 round).
Primary Stat Increase
+1 DEX or INT.
Contingency
Choose a Contingency.
Urban Operator
Gain a climb speed. You can move through other creatures spaces without penalty, and ignore difficult terrain from crowds.
Secondary Stat Increase
+1 STR or WILL.
Careful Aim
(1/turn) If you don't move on your turn, you can aim for free with Advantage.
Aim(2)
Your aim increases to 2d8.
Contingencies
Mobile Aim
(1/Turn) When you Aim, you can move for free.
Weakening Shot
On crit: the target's next attack takes a -10 to damage.
Kill Steal
Reaction: when an ally crits an enemy, aim and make an attack against the target for free.