Extremely heavy balance changes:

Marksman is a direct combat kit.
Sniper is a fire support kit. x6 scope and suppressor.
AMR Sniper available as a specialist kit. x4 scope except for CAF, which gets a x6 scope.
Scout kit (below)

Light Grenadier as a direct combat kit, using both rifle grenades and thrown.
Heavy Grenadier as a specialist kit using multiple grenade launchers.
Commando kit (below)

Light AT is a direct combat kit. It has only one disposable AT launcher.
Disposable AT Launchers cost 60 ammo to rearm.
New Medium AT role carrying reusable AT launchers with 3 rounds.
Air Defense role with anti-air launchers, with 3 rounds too.
HAT role gets top-attack launchers, also with three rounds. In factions without either MANPADS or top-attack launchers, instead they get a reusable AT launcher with 6 rounds of ammunition, split into three types to accomodate multiple target categories.

Telecomms Operator, Commando, and Scout kits for secondary rally placement. Telecomms for UAV, Commando for light mortar, Scout for scout rifle. All three are specialists. Only scout doesn't carry suppressed automatic weapons out of the three.

Pioneer kit in direct combat role with current non-explosive engineer tools.
Sapper in fire support role with UGVs on conventional, UAVs on irregular. Unconventional sappers are the only ones with AT mines unless the faction lacks engineers.
Engineer remains in specialist role, gains UAV on unconventional/middle power, UGV on superpower and a remote-controlled explosive.
Telecomms Operator part of Engineer class.
UAVs, UGVs, sandbags and barbed wire cost construction supplies, not ammunition or tickets.

Remote Gunner kit available as specialist kit with a SAW UGV and a PDW. SAW UGV can't be reloaded without an ammo bag, and can't be repaired without an ammo crate.

Technician role to separate medics, crewmen, and low-intensity combat kits from heavy fire support roles and make kit limits clearer.

Breacher kit in direct combat role with shotgun, underbarrel shotgun and scoped rifle, or an automatic shotgun.

Ghost kit with suppressed weaponry and tactical flashlight in direct combat role. Only available to superpower factions.

Flamethrower kit in direct combat role for unconventional forces only. Also carries molotov cocktails and 30s timed TNT charges.

Only two fire support or specialist kits per squad. Only three fire support kits of each variety per team. Only one specialist kit of each variety per team. Doubles of one class of kit (precision, grenadier, machine gunner, engineer) only allowed if SL equips a matching leadership kit. (Thus, an SL chooses what his squad's specialty is.) Otherwise only one of each class of kit permitted.

Decoys: These deployables can be placed to imitate the presence of a tank or IFV. These are useful in case you want to make an attack helicopter waste ammo or bait out AT into firing on these targets. They inflate in 10 seconds. These are susceptible to normal bullets, deflating in 1 minute with 1 round and 6 seconds with 10. They can be built on FOBs.

Sandbags and barbed wire cost building materials to restock for engineer kits.

New resource type: Electronics. This resource is used in some deployables and some kits require it to restock radio jamming devices, rally points, UAVs, or UGVs.

ATGMs cost 300 build and 200 elec for conventional factions, making them cheaper but more logistically complex.

Radar - detects airborne vehicles within the FOB denial radius (the grey one). Costs (conventional) 900/300 (unconventional) electronics to build and takes a long time to construct, and must have a radar display deployable placed to view what's going on in the device. Natural objects will interfere with the radio's performance so it must be placed in a high position for maximum resolution.

Radar display screen - Costs 100 electronics to build and must be manned in order to observe what's happening on radar.

Redundant FOB radio - secondary radio that prevents the main FOB from bleeding out in the event that an engineer gets to it and in case it gets jammed. However, they have significantly less health, being unable to withstand a single C4 charge or HAT round. Costs 1000 electronic materials to build. Maximum 2 per FOB.

Five tiers of kits:
Command
Mission Support
Direct Combat
Fire Support
Specialist

Seven classes of kits:
No limits (Breacher/Rifleman/Crewman/Pilot/Medic)
Sapper (Scout/Engineer)
Anti-Tank (HAT/AT Gunner)
Grenadier (Heavy Grenadier/Commando)
Gunner (MG/Flamethrower)
Sniper (AMR/Scout)
Squad Leader

Six SL templates:
Engineering SL - red dot sight carbine, sandbags, barbed wire
AT SL - iron sight carbine, one frag
Grenadier SL - red dot sight carbine, two frags
MG SL - frontal grip assault rifle, one-two frags
Sniper SL - scoped assault rifle, one frag
Lead Pilot/Crewman - Pilot/Crewman with stomp-proof rally point, (still becomes disabled when enemy in proximity) extra smoke grenades and night vision goggles.

No faction has every kit.

Regions:

Central Asia
With the least amount of changes to the base game, watch the three major powers slug it out against each other and against the remains of islamic fundamentalists in open desert and cramped cities.
Desert, Urban, Mountain
USMC, PLA, RUS, AUS, IAF, ISIL

Mongolian Border
China, Russia, and North Korea cause a lot of noise for a country with a rich heritage and a wish for everyone to get along...
Desert, Mountain
PLA, RUS, DPRK, ISIL

Korean Peninsula
North Korea is engaged in a vicious war against the rest of asia. The Free Asia Pacific Alliance formed in response to waning American power, and to consolidate their strength against Korea's biggest neighbor...
Forest, Urban, Mountain, Island, Snow
RUS, PLA, USMC, FAP, DPRK

Himalayan Mountains
Historians in this setting point to the China-India border skirmishes of 2020 as the catalyst for China's increased aggression. Helicopters perform poorly in this region. Islamic fundamentalists also are trying to make a foothold in this region, but perhaps India and the USA could make a deal...
Mountain, Forest, Snow
PLA, IAF, ISIL, NARC

Indochinese Peninsula
China, SEAR, and Taiwan are at each other's throats and even PMCs like Constellis are involved in assisting the combatants.
Jungle, Island, Swamp
PLA, USMC, AUS, IAF, FAP, DPRK, SEAR, ISIL, NARC

Southeast Asia
Jungle, Island, Swamp
PLA, USMC, AUS, IAF, FAP, DPRK, SEAR, ISIL, NARC

Micronesian Islands
Jungle, Island, Swamp
PLA, USMC, AUS, FAP, SEAR, DPRK

Mainland China
Urban, Forest, Jungle, Mountain, Desert
PLA, RUS, IAF, FAP, NARC, DPRK, SEAR

Australian Continent
Urban, Desert
PLA, AUS, SEAR, NARC

Virtual Scenario
Giant dinosaur carcasses, polygonal modern art skyscrapers and fields of blooming pies, this humorous scenario is filled with impossible faction matchups that otherwise can't be experienced.
Snow, Urban, Forest
USMC, AUS, FAP, SEAR