You have a good idea there, with checking each other's work.
For one - the lamia's wisdom drain should only be 1st level. I know it sounds overpowered at first glance (I thought the allip's wisdom drain was, as well), but comparing it to ray of enervation, which deals 1d6+1/2 caster levels worth of Str damage and is 1st level... I think that the wisdom drain abilities are around that power level, if not weaker, since they don't scale.
Rejuvenation - I don't know what to make of that one... that's certainly an odd ability. Using it in an example, I would think that the character would (for purposes of LEW) just return to the inn it frequented in life. How that would function, I have no idea... for instance, when would the learner cast the spell? Right before death? Would it have a duration, and if the character died in that duration, he comes back at the inn? As a 9th level spell, I think it works... it's vaguely on par with the bring-back-the-dead spells at that level, though it accomplishes it in a really weird fashion.