Best would be to create a TEMPLATE

Grant All Skills as Class Skills <tab> CSKILL:ALL

Then add that to your characters for that game.

From the documentation:

*** Updated 5.13.6

Tag Name: CSKILL:x|x

Variables Used (x): Text (<Skill Name>)

Variables Used (x): Text (Type=<Skill Type>)

Variables Used (x): ALL

Variables Used (x): LIST

Variables Used (x): .CLEAR

Variables Used (x): .CLEAR.Text

What it does:

• Grants the listed skills as class skills.
• When used in a Class LST object it grants the class skills only to the class it is actually in.
• When used in a Domain LST object it grants the class skills only to the classes that grant the domain.
• When used anywhere else it grants the class skills to all classes the character possesses.

Examples:

CSKILL:Listen|Spot

The "Listen" and "Spot" skills are made class skills.

CSKILL:Search|TYPE.Knowledge

The "Search" and "Knowledge" type skills are made class skills.

CSKILL:ALL

All skills are made class skills.

CSKILL:LIST

Skills selected in the associated choice are made class skills. (In Abilities and Feats)

CLASS:Sorcerer.MOD <tab> CSKILL:.CLEAR.Scry <tab> CSKILL:Drive|TYPE.Knowledge|Perform

Modifies the Class Sorcerer, droping the class skill "Scry" and adding "Drive, Perform and all TYPE.Knowledge" skills.

CLASS:Blackguard.MOD <tab> CSKILL:.CLEAR <tab> CSKILL:Concentration|TYPE.Craft|Diplomacy|Heal|Intimidate|Knowledge (Religion)|TYPE.Profession|Climb|Jump|Listen|Spot|Swim|Pilot

Modified Class that removes all class skills in the object previously, then adds in the specific list.

CLASS:Blackguard.MOD <tab> CSKILL:.CLEAR.Handle Animal|.CLEAR.Ride|Heal <tab> CSKILL:Pilot

Modified Class that removes only Handle Animal and Ride from the original class skill list, and then adds Heal and Pilot.