I think the variants that Sollir Furryfoot links to are a little too close, mechanically, to the warlock. Mechanical closeness is to be legitimately expected when you use the word "variant," I suppose, but in this case it leads to some odd results. The "Gifted" (celestial warlock) substitutes doves and daylight instead of bats and darkness for Hungry Darkness. The image of doves pecking people to death just strikes me as wrong. Although at least the light isn't mechanically equivalent to darkness- a dazzling glare, or something. But still- being pecked to death by celestial doves?
@Drowbane: I think it would cause too much confusion to use the name Favored Soul. People would think you meant the other class.
And I'm thinking "stream of purity" or "celestial stream" instead of "curative blast." I think it should definitely be a default power (like eldritch blast is for the warlock) that converts a living target's lethal damage to non-lethal damage, and that damages undead. Different upgrades would allow it to affect fiends, aberrations, or constructs, improve the range, and so on, if that was the cabalist's schtick.
@Felon: I don't think it is necessary to mechanically limit the amount of healing the character can do. If it needs to be limited, I'd think that the lethal => nonlethal mechanic is sufficient. Parties would still need several hours rest to get back to full strength after a difficult battle. But I think that having parties being able to get their full hit points back after each battle should't be a problem. Maybe lethal => nonlethal at low levels, and real curing at mid levels?
@Jackelope King: A nice set of powers, but I'm afraid my mind is still focussing on what the cabalist needs to fulfill the cleric's niche. Kinda like how a druid can fill in for a cleric... mostly. So I'm thinking more about Suppress Ailment types of powers and stronger variations (I still think the duration is a little low.) Need some way to deal with paralysis, blindness, ability damage/drain, curses and negative levels. And raising the dead. The cabalist will probably have more powers than a warlock so that it can fulfill many (if not all) of these niches and still have options left that make the class fun to play. The abilities you list all look like fun, btw.
....Just looked at your list again. Do you think the "purity" theme might be laid on a little heavy? Seems a bit repetitive in that first section. Nice names for the rest of them, though.