I want to discuss one change, but anyone fire away with others:
Made the following spell changes based on Ravenloft PnP books:
...
-Searing Light: The Dread Realm gives certain advantages to undead creatures. In Ravenloft, undead creatures can make a Will save for half damage.
Can you cite the PnP book on which you based this change?
I've looked at
Domains of Dread and can't find it in there among the listed changes, but I might be looking at the wrong edition. In fact, the only "searing light"-type spell I find altered is "searing orb," and it's actually enhanced:
Sol's Searing Orb: The light from this spell is considered to be the equivalent of daylight. Therefore, in addition to normal damage inflicted by this spell, it harms creatures affected by daylight as if they were standing outside on a bright summer day.
Second, Searing Light is supposed to do 1D8 per caster level against undead already but only does 1D6 in NWN. So it's weaker than it's supposed to be in PnP.
It requires a ranged touch attack, affects only one target, and spell resistance applies. As someone who actually uses it (most people who know how to play tell me I'm stupid to waste a well slot on it), I can tell you it hardly needed nerfing. I expended three uses (9 charges total) of a magic item with it recently for a grand total of 0 points of damage against a vampire. Iridni's innate casting of it tends to be more effective, but this is her niche.
A Will save? How does that make sense? I understand that the Will save might be so mindless undead are still susceptible to it, whereas more powerful undead (VAMPIRES!) are less likely to be, but the entire usefulness of the spell is...those creatures most susceptible to sunlight. The mechanic of implementing a Will save seems to be for a desired outcome rather than having any rational basis in realism.
As is, the best use I've found for the spell is to finish off fleeing enemies that I couldn't run down easily. I slot it because it seems dumb to be a Sun Domain cleric and not ever employ it.