I've been reading up on holy powers a little, and I found several issues in tCI that I have not seen addressed in errata:
The tradition Céli Dé (p 138) has as its Favored Abilities Invocation, Intervention, Purity, and Transcendence. There are no guidelines in RoP:D for using Invocation with either Intervention or Transcendence. I guess the second Method should probably be Meditation. (In addition, all Traditions in RoP:D have Favored Abilities from three Major and one Minor Virtue, so IMO it would be even better to replace Invocation with an ability from a Minor Virtue.)
The Ex Misc tradition at The Paruchia Nerius (Hermetic Céli Dé, p 65) gain Holy Magic as their Major Virtue. They also get Holy Magic as a Favored Ability - is not the point of a Favored Ability to remove the need for the Virtue?
Also, the character Indrechtach an t-Éigse Measceal (p 66) has Intervention 4 (Transcendence), a specialty that makes no sense. It should be Intervention 4 (Purity).