Could call them masteries, competencies (or comps), tricks, specializations (or specs), (your suggestion here) (I kind of don't like calling them feats, but I am using that name for now because they mostly fill the same role dnd feats do.
These are specific abilities with a cost in experience and usually prerequisite skill ranks that you buy once. They are a good place for things that not everyone who learns a skill might learn, new tricks that require multiple skills, and things that have only a few discrete levels of ability (say armor skill).
In some cases they will replace skills that didn't really work that well (armor skills). Eventually, once we get many of them (50+) characters will be able to have different ones and thus two fighters with 12 ranks in <relevant combat skill> will still not feel identicalish.
These should be treated as examples for now, they are subject to heavy modification or elimination
Heavy Armor: Proficient
Prereqs: Combat 1 rank
Benefit: You may wear heavy armor without suffering skill penalties
Heavy Armor: Expert
Prereqs: Heavy Armor: Proficient, Combat 2 ranks
Benefit: reduce the effort multiplier for heavy armor to 1.75 (from 2.0)
Heavy Armor: Master
Prereqs: Heavy Armor: Expert, Combat 3 ranks
Benefit: reduce the effort multiplier for heavy armor to 1.5
Secondary Attack (rename)
Prereqs: Any weapon 8 ranks, Any unarmed 8 ranks
Benefit: If you are less than 6 ticks from ready you may make an unarmed or light weapon attack at a -2 penalty. Add the delay for this new attack to your delay.
Prereq: any social 6 ranks
Benefit: Reduce wit fatigue penalty by 1
Prereq: any intellectual 10 ranks
Benefit: Reduce focus fatigue penalty by 1
Prereq: any body 6 ranks
Benefit: Reduce wind fatigue penalty by 1
Prereq: any body 10 ranks
Benefit: Reduce stamina fatigue penalty by 1
Prereq: Weapon 5 ranks, distract 5 ranks
Benefit: You make an attack one category faster and spend half as much effort. If the attack hits, it deals half damage. Make a distract aided by weapon skill roll opposed by weapon skill aided by awareness. If you win the check, the defender must spend full effort to defend against the attack, otherwise they spend as normal for the increased speed.