Greater restoration should work, since it "dispels all magical conditions penalizing a creature's abilities", but its lesser kin would have no effect since they only affect ability damage or drain, not penalties.
I'd also allow limited wish, miracle, and wish, should they want to spend those kind of resources.
Right - it's a Personal spell, so it's eligible for the Share Spells ability that lets you cast the spell on the familiar.
You tell the familiar which questions to ask, and if it fails and he gets zapped, you just cast it again - normally, the ability decrease would prevent you casting the spell again, but since your abilities are unaffected, you're good to go...