Here's some suggestions to add/modify (a bit Army-centric in worldview, but hey -- that's what I know):
Air Assault Training – (ath) Rappelling, (ath) Break Fall
I'd add "Sling Load", since that'ts really the major skill AA teaches -- how to prep stuff to be moved by Helo. AA is a fun bonus.
Armor – (drv) Tracked, (ops) Artillery, (ops) Sensors, (ops) Communications, (ops) Vehicle Weapons, (ops) Navigation
Depending on how you define the skill, Armor and Artillery are not remotely the same. Armor (tanks & cavalry) is a direct fire maneuver capability; Artillery is indirect fire that in some forms uses a tracked vehicle to move from firing position to firing position. I'd make Artillery its own MOS, with skills like Heavy Weapons, Communications, Navigation, Calculation, Rockets, and Precision Fires. You could roll in mortars, too, though both my Infantry and Field Artillery brethren would kill me for suggesting it (Mortars are an Infantry system but have a lot of skills common with Field Artillery, and the Artillery tends to feel a bit threatened; the Infantry is always afraid the Artillery wants to take their mortars away).
Aviation Support – (ops) Air Traffic Control, (ops) Sensors, (ops) Communications, (ops) Aviation Support, (eng) Electronics, (eng) Mechanical, (eng) Aircraft Mechanic
Combat Engineering – (drv) Big Rigs, (drv) Tracked, (eng) Bridging, (eng) Demolitions, (eng) Electrical, (eng) Mechanical, (eng) Structural
In the Army, Combat Engineers and Construction Engineers are different fields in the same branch. The Combat guys get the demolitions, mine laying, mine clearing, and fighting position work plus Infantry skills; the construction guys build bridges, drive construction equipment, build buildings and airfields, handle electrical work, and in general the rest of the "engineering" skills.
Defense Language Institute – (aca) Choose two Languages
Desert Warfare College – (sur) Desert Training, (drv) Desert Driving
Diver – (ath) Swimming, (ath) Breath Control, (ath) Diving, (eng) Demolitions, (eng) Electrical, (eng) Mechanical
Field Artillery – (ops) Artillery, (eng) Structural, (eng) Demolitions, (ops) Missile Gunnery, (eng) Structural
Infantryman – (rng) Heavy Weapons, (rng) Rifle, (eng) Demolitions, (tac) Patrol Scale Ambush, (tac) Human Trapping, (tac) choose one Terrain
Demolitions tends not to be a skill taught to many MOS -- as I recall, other than basic mine training common to all MOS (and technically, mines aren't demolitions), only Combat Engineers, Scouts, and EOD techs have real demolitions training as part of their core MOS. Other folks can pick up some basic skills, but there's a huge difference between knowing how to arm a block of C4 with a bit of det cord and time fuze and setting up a ring main or calculating the right amount of explosive and placement to construct an abatis or drop a bridge. (Hint: the P stands for "Plenty". Sorry ... demo joke most folks won't get).
I'd recommend adding an EOD MOS, too, for the real demolitions and ordnance specialists. Could be a prestige class sort of thing if you want.
Jump School – (ath) Parachute, (ath) Break fall
Jungle/Swamp Warfare College – (sur) Jungle Training, (sur) Swamp Training, (eng) Demolitions
Law Enforcement – (tac) Police Tactics, (per) Spot Criminals, (per) Detect Lies, (per) Crime Scene Investigation, (per) Spot Concealed, (prs) Interrogation, (prs) Gather Information, (ma) Grappling Basics,
Most MPs/SPs are "Grunts with a skill" in that they have infantry skills as well -- one of their main functions is Route and Rear Area security, which is basically an Infantry mission performed with too few people and no supporting artillery.
Maintenance – (eng) Electronics, (eng) Mechanical, (eng) Communications
Medical – (med – Focused) NBC treatment, Psychology, Pharmacology, Bush Medicine, (sci) Biology, (sci) Chemistry, (ops) Hazmat Containment
Mountain Warfare College – (sur) Mountain Training, (ath) Climbing, (ath) Rappelling, (eng) Demolitions
NBC Warfare – (sci) Chemistry, (sci) Chemical Weapons, (ops) Hazmat Containment
I'd add "Chemical Defense", "Nuclear Defense", "Nuclear Weapons" and "Chemical Reconnaissance" to the NBC skills, and make "Chemical Defense" something most characters can pick up. Oh, and the replacement term for NBC among the cool kids these days is CBRNE (Chemical, Biological, Radiological, Nuclear, & (High Yield) Explosives).
Pilot – (plt) Air Recon, Dog-Fighting, Escort, Formation, Strafing, Choose Helicopter or Jet Fighter, (eng) Electrical, (eng) Mechanical, (tac) Air Combat Tactics, (ops) Communications, Missile Gunnery, Navigation, Sensors, Vehicle Weapons
Don't forget "Crew Rest" and "Tall Tales at the Club".
SERE – (sth) Evasion, (wil) Resist Torture, (wil) Resist Persuasion, (wil) Resist Intimidation
Signals – (hrd) Networking, (ops) Communications, (eng) Electrical, (eng) Communications
Signals Intelligence – (hrd) Networking, (ops) Communications, (aca) Linguistics, (aca) Cryptography, (ops) Electronic Warfare
Urban Warfare College – (tac) Urban Combat, (eng) Demolitions, (ath) Climbing, (ath) Rappelling
UAV Operations – (ops) Air Traffic Control, (ops) Drone Control, (plt) Air Recon, (plt) Strafing, (ops) Sensors, (ops) Electronic Warfare
Other ideas include:
Recon/Scout: Infantry Weapons, Demolitions, Vehicle Operations, Stealth, Sensors, Communications, Navigation
Commando: Assault Tactics, Language, Culture, Demolitions, Light & Heavy Weapons, Airborne & Air Assault, Communications
Sniper: Light Weapons, Stealth, Long Range Precision, Communications
Logistician: Maintenance, Supply, Transportation, Planning, Calculation
Civil Affairs: Government, language, culture, diplomacy, planning
PSYOPS: Language, culture, media arts, diplomacy, bluff, deception
REMF: Administrivia, Fobbitry, Coffee drinking, brown-nosing