I can't really speak to a lot of your question but in looking at your pdf.
Your Aura of protection strikes me as a wizardly thing and extremely good for a class power. It would feel better to me if it was a resist to Necrotic only and had had a high sustain cost. (And resist Radiant for evil aligned paladins, where as neutrals could pick one or the other at character creation). Or perhaps limit it to the end of your next turn but bump the resistence up so it's a one shot
The swallowing of a creature's soul to empower your own attacks strikes me as un-good, that would make a good ption for an evil aligned paladin but not so much as an good one. If you want keep that then perhaps changing the name to "Righteous Fervor!" and making it an encounter power only. I would worry that this will lead to metagaming where the paladin's player actively marks creatures even one's it's not fighting but ones taht are about to die just to get this buff. A one time per encounter damage buff would help curtail that kind of gaming I think. Or add the limitation like hunter's quarry which is a straight damage buff that it has to be the nearest creature.
Anyway those are my initial reactions after reading your document, they could easily be quite mistaken but there ya go.
