Here is a list of all the identified psionic functions along with a brief synopsis of their parameters and what they represent:
From psi_inc_core.txt

- GetPowerLevel(object oManifester)
  - oManifester: The creature object manifesting power. This function retrieves the psionic power level of the creature.
  
  
From psi_inc_psifunc.txt

- EvaluateManifestation(object oManifester, object oTarget, struct power_augment_profile pap, int nMetaPsiFlags)
  - oManifester: The creature that is attempting to manifest the power.
  - oTarget: The target of the power.
  - pap: A structure containing parameters outlining how the power may be augmented.
  - nMetaPsiFlags: Bit flags indicating which metapsionic powers might apply during this manifestation.
  
- UsePower(int nPower, int nClass, int bIsPsiLike = FALSE, int nLevelOverride = 0)
    - nPower: Identifier of the psionic power to use.
    - nClass: Class identifier from which the power is being used.
    - bIsPsiLike: Boolean flag specifying whether the power being used should be treated as a psi-like ability.
	- nLevelOverride: Optional parameter to override the default power level.
	
- DebugManifestation2Str(struct manifestation manif)
      - manif: Struct containing data about the current psionic manifestation—used to generate a string for debugging purposes.
	  
- SetLocalManifestation(object oObject, string sName, struct manifestation manif)
        - oObject, sName: Target object and the string name under which this data is stored.		
        - manif: Data about the current psionic manifestation to store.
		
- GetLocalManifestation(object oObject, string sName)
          - oObject and sName: Retrieve stored manifestation data from the object using the given name.
		  
- DebugIgnoreConstraints(object oManifester)
            - oManifester: Creature to ignore psionic constraints for debugging.
			
- EvaluateDiaDragChannel(object oManifester, object oTarget, struct power_augment_profile pap, int nPowerLevel)
              - Similar to EvaluateManifestation but tailored for specific channeling functionality in psionics.
			  
			  
From psi_inc_metapsi.txt

- EvaluateMetapsionics(struct manifestation manif, int nMetaPsiFlags)
  - Describes how metapsionic modifications affect the current psionic power manifestation.
  
- PayMetapsionicsFocuses(struct manifestation manif)
    - Calculates costs in terms of psionic focuses for using metapsionic modifications.
	
- MetaPsionicsDamage(struct manifestation manif, int nDieSize, int nNumberOfDice, int nBonus = 0, int nBonusPerDie = 0, int bDoesHPDamage = FALSE, int bIsRayOrRangedTouch = FALSE)
      - Calculates how metapsionics affect the damage output of a psionic power.
	  
- EvaluateWidenPower(struct manifestation manif, float fBase)
        - Determines the effect of the "Widen Power" metapsionic on the area of effect size.
		
- EvaluateChainPower(struct manifestation manif, object oPrimaryTarget, int bAutoDelete = TRUE)
          - Builds a list of secondary targets for chained psionic powers.
		  
- GetSplitPsionicRayTarget(struct manifestation manif, object oPrimaryTarget)
            - Identifies an additional target for the "Split Psionic Ray" metapsionic.
			
			
From psi_inc_augment.txt

- PowerAugmentationProfile(...)
  - Sets up a profile detailing how a psionic power can be augmented.
  
- GetUserAugmentationProfile(object oUser, int nIndex, int bQuickSelection = FALSE)
    - Retrieves a user-defined configuration of how they want their psionic power augmented.
	
- GetCurrentUserAugmentationProfile(object oUser)
      - Retrieves the current, active augmentation profile for a user.
	  
- StoreUserAugmentationProfile(object oUser, int nIndex, struct user_augment_profile uap, int bQuickSelection = FALSE)
        - Stores or updates a psionic augmentation configuration.
		
- UserAugmentationProfileToString(struct user_augment_profile uap)
          - Converts an augmentation profile to a human-readable string.
		  
- EvaluateAugmentation(struct manifestation manif, struct power_augment_profile pap)
            - Applies user-defined augmentations to a psionic power manifestation to adjust its effects.
			
- SetAugmentationOverride(object oCreature, struct user_augment_profile uap)
              - Allows overriding the current augmentation settings forcibly.
			  
			  
From psi_inc_ppoints.txt

- GetCurrentPowerPoints(object oChar)
  - Retrieves the current power points of a character.
  
- GetMaximumPowerPoints(object oChar)
    - Calculates the maximum power points a character can have.
	
- GetPowerPointsAsString(object oChar)
      - Gets a string representation of both current and maximum power points.
	  
- TellCharacterPowerPointStatus(object oChar)
        - Displays a character’s power points.
		
- ResetPowerPoints(object oChar)
          - Resets a character’s power points to maximum.
		  
- GainPowerPoints(object oChar, int nGain, int bCanExceedMax = FALSE, int bInform = TRUE)
            - Increases a character’s power points, possibly beyond the maximum.
			
- LosePowerPoints(object oChar, int nLoss, int bInform = TRUE)
              - Deducts from a character’s power points without going below zero.
			  
- LoseAllPowerPoints(object oChar, int bInform = TRUE)
                - Sets a character’s power points to zero, including notification.
				
These functions manage various aspects of psionic powers in the game, including their initialization, application, augmentation, power points management, and interactions with metapsionic abilities.