Thor's Lightning seems indeed to be a rebranded Lightning Bolt, the same way Thor's Might seems to be a re-branded Righteous Might (especially since Durkula could cast Hel's Might, which appears to work the same).
Could Cat's Grace be an holdover from 3.0? I know it wasn't 100% by-the-rules, but I remember the first Neverwinter Nights had Cat's Grace available to Clerics through a domain (Animal, I think), and it was based on the D&D 3.0 rules.
EDIT: Unrelated, but why isn't Tarquin listed as having the Snatch Arrows feat? He uses it at least two times, complete with "snatch" sound effect.