Below are the features of Core Skill Overhaul

1. Survivor Stats set to a lower baseline
Survivor's can carry less weight overall, don't have great minimap radar, and start with 4 pockets.
2. Cardio and 4 Specializations
The Cardio Skill Tree is now called Movement and includes 4 Specializations: Survivalist, Parkour, Hunter and Mule.
Cardio/Movement grants your character more stamina and some carry weight when maxed.
Marathon/Survivalist is the default/recommended Specialization which has decent stamina, sprint for free when light and decent carry weight.
Acrobatics/Parkour is the flashy Specialization which has the dodge roll, sprint for free when light and a low carry weight.
Backpacking/Hunter is the "fighting" Specialization which has the cheapest dodge, lots of stamina and a bit more carry weight than Survivalist.
Powerhouse/Mule is the heavy Specialization which can carry the most and has the most stamina.
3. Wits and 3 Specializations
The Wits Skill Tree is now called Awareness and includes 3 Specializations: Survivor, Scout, and Looter. Everyone unlocks sprinting when crouched and silently opening doors during their specializations. If the character gets to the specializations they all end up with the standard 3 stack size for consumables by the end of their tree.
Wits/Awareness grants your character faster search, better minimap radar and higher consumable stacks.
Discipline/Survivor is the default/recommended Specialization which strikes a balance between looting fast, minimap radar and sneaking.
Scouting/Scout grants you the best minimap radar and sneaking ability but not the greatest looting abilities.
Resourcefulness/Looter gives you the best looting abilities like seeing all containers in unsecured buildings.
4. Fighting and 4 Specializations
The Fighting Skill Tree is now called Melee and includes 4 Specializations: Fighter, Swordsman, Knife Fighter and Brute.
Fighting/Melee grants your character more health and special combat abilities.
Striking/Fighter is probably the best Specialization and focuses on crowd control.
Swordplay/Swordsman balances crowd control but focuses on killing zeds quickly. 
Close Combat/Knife Fighter focuses on stealth kills and finishing enemies as quick as possible. 
Endurance/Brute focuses on using Heavy Weapons and Grappling. 
5. Shooting and 3 Specializations
The Shooting Skill Tree is now called Ranged and includes 3 Specializations: Commando, Marksman and Specialist. Everyone unlocks the ability to unjam weapons at Level 5 of Shooting and doubling in Ammo Stacks.
Shooting/Ranged grants your character better weapon handling and the ability to unjam firearms.
Weapon Handling/Commando is the standard specialization which has decent weapon handling and focuses on using the Aim Snap ability.
Sharpshooting/Marksman is the gun expert who can unjam weapons quickly and eventually unlocks Aim Snap, also handles guns best.
Assault/Specialist is the odd "support" skill which gets to stack consumables an extra 2, better bolt recovery and reloads the fastest.
Note: Everyone can unjam guns but it's not displaying properly on all Skills.
6. XP
XP Curve is as follows: Base Skill Level 1 - 500, 2 - 600, 3 - 700, 4 - 800, 5 - 900, 6 - 1000, 7 - 1500
Specialization Skill Level 1 - 1000, 2 - 1100, 3 - 1200, 4 - 1300, 5 - 1400, 6 - 1500, 7 - 2000
For Cardio/Movement, you need to move 10 meters to get 10 XP which means you need to move about 4 miles to get to the specializations. You will gain 5 XP after specializing which means you will need to move about 6 miles to complete your specialization. You will gain 1 XP for a hit with any melee weapon.
For Wits/Awareness, you get 20 XP for stealth kills and looting a container, which means you need to stealth kill or loot 300 zeds/containers to get to the specializations. The specializations earn XP at slightly different rates, ie: Scout gets more XP for stealth kills (30) and looter gets more XP for looting (30).
For Fighting/Melee, you get 30 XP for a kill and 5 XP for a hit, 20 XP for a finisher and 15 XP for a Stealth Kill, this means you need to kill about 300 zeds to get to the specializations. The specializations earn XP depending on what weapon you are using. Knife Fighter gets 1 XP for a hit and 30 for a Kill regardless of if it's a CC kill, Stealth Kill or a Finisher. Fighters get 10 XP for a hit, 20 XP for a kill and 5 XP for finishers and stealth kills. Swordsmen get 5 XP for hits, 30 XP for kills, and 15 XP for Stealth Kills or Finishers. Brutes get 10 XP for hits, 20 XP for kills and 5 XP for stealth kills and finishers.
For Shooting/Ranged, you get 20 XP for a kill with a gun and 1 XP for a hit, also you will receive 1 XP for an Explosive/Fire hit and 5 XP for a Explosive/Fire Kill, this means you need to kill about 300-1200 zeds to get to the specializations. The specializations earn XP differently. Commando gets decent XP from shooting zeds (20/10) and a little bit from blowing them up (10/5). Marksman gets great XP from headshoting zeds (30) and a little bit from shooting them and next to nothing for blowing them up (1/1/1). Specialists get decent XP from shooting zeds (15/5) and a lot of XP from blowing zeds up (30/10).
7. Clean up - (WIP)
Replaced all skills, including heartland but excluding daybreak with their custom counterparts.
8. Other Mods - (PLANNING)
I plan to allow 1 more additional item stack with sewing or some other community skill, this will be addressed in a separate Community Skill/5th Skills mod.

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Full List of Skills and their Vanilla Replacement

Cardio - Movement
Marathon - Survivalist
Acrobatics and Gymnastics - Parkour
Backpacking and Prowess - Hunter
Powerhouse - Mule

Wits - Awareness
Discipline, Field Testing and Obsession - Survivor
Scouting, Stealth, Tactics and Vigilance - Scout
Resourcefulness and Scavenger - Looter

Fighting - Melee
Close Combat and Heroism - Knife Fighter
Striking - Fighter
Swordplay and Butchery - Swordsman
Endurance - Brute

Shooting - Ranged
Weapons Handling, Gunslinging and Warfighting - Commando
Sharpshooting - Marksman
Assault - Specialist

Note: MORALE BUFFS HAVE BEEN REMOVED (Probably permanently)