I do play with max hp per level, but I also have a tweaks anthology component that maxes out the hp of all creatures in the game.
Looking at the d5_ckit script, the Jaheira proficiencies issue seems to affect all multi-classed characters below a certain xp threshold. Since I'm trying to recruit her in the BG1 portion of EET, she's well below the threshold. Here's the block that's responsible:
IF
Class(LastSummonerOf(Myself),FIGHTER_DRUID)
Global("D5CHACLS","GLOBAL",2)
Global("D5STTTLK","GLOBAL",1)
CheckStatGT(LastSummonerOf(Myself),22000,XP)
THEN
RESPONSE #100
ActionOverride(LastSummonerOf(Myself),ApplySpellRES("D5_CPR1",Myself)) // No such index
Continue()
END
Removing the xp condition fixes the issue but I assume it's there for a good reason and removing it could have unintended consequences elsewhere.
As a druid and without spell revisions, Jaheira wouldn't normally be able to cast zone of sweet air since it's a cleric-only spell, but she has that ability on account of being a harper, I guess.