Can't buy psi abilities

[Execlectic]

1.0.0.10, All my actual psi abilities are 23, with my effective at 30, I can't purchase any abilities from any trainer at 25, 30. As far as I can tell, this is only applying to psi (lockpicking/hacking work, items show white text instead of red).

[Fenix]

Only real lvl of skill counted towad learning ability, not effective level, which is demonstation your overall perfomance in skill.
Like you need specific skill to master ability, but effective skill shows how good you are in that.

[Execlectic]

Is that so? In doing my research, it seems to me psi ability level is for only one thing, to unlock new spells? It doesn't influence damage or anything else? If that is the case why have synergy at all?

[Execlectic]

Sorry to bother, I know this seems to be not a bug? I am very confused as to the purpose of psi skill synergy or items such as psionic headbands as I can find nowhere in the wiki or online that says that specific psi skills are for anything other than new spell purchasing (and feats).

My question is:

Do psi skills affect anything aside from feats and spells? Do they influence damage within the specific school? Or resist checks? What is the purpose in having a skill higher than your base?

edit: Epeli: In other words, what is "pretty much everything else"?

[Execlectic]

D'oh, I never looked at any specific ability, only general information concerning Psi. Thank you very much! I appreciate your help!