I have the same reading as Eric.

Passive of 18 is the equivalent of a passive stat of 3 and 3 ranks.

If you also added passive charisma then it would be equivalent of 6 ranks of Arcanium + passive charisma

Too much for base rune IMHO but I too will wait for the Stat Monkey to speak with his poorly spelt wisdom <GRIN>

For the spell Ward Against the Unnatural, on ARPG p.442 there is a special adaptation for the Blood tradition. Does this Blood adaptation work against any type of person or creature, or is it only against one individual Undead, Shade, or Infernal as per the base spell?

I interpret it as being against any type of person or creature for whom the caster posses blood, but the adaptation is not explicit.

For the spell Steal Water, on ARPG p.430, there is a special adaptation for the Blood and Heritage traditions to enhance single a Blood spell. In what time frame does this follow-up need to be cast to take advantage of the bonus?

I could see it being any of the below:
* The Blood spell is cast as part of the Steal Water spell--though how they'd be combined isn't clear from the Steal Water description.
* The Blood spell must be part of the caster's next action.
* The Blood spell must be cast within a certain number of ticks--though the number of ticks needs to be determined.
* The Blood spell must be cast during the same scene.

For the Talents Rudimentary Prayers and Rudimentary Spell Casting (see ARPG pp.204-05), must the single spell selected be Tier I, or may it be any Tier?

I infer that it should have to be a Tier I spell, but the talents are not explicit.

Does the ability to use Arcanum(Sorcery) untrained via the Bloodline Talent Sarish Is Known to His Chosen (ARPG p.222) count for the prerequisite of having Arcanum (Sorcery) as a trained skill?

It is technically not trained, but since val'Mehans with that Bloodline Talent can cast spells instinctively, I can easily see it being a sufficient substitute. This question matters mostly for learning spellcasting, which val'Mehans can already somewhat do via their bloodline, but most spellcasting talents (e.g., Arcane Spell Casting on ARPG pp.185-86) have prerequisites.

Given the Valinoric source of the val'Mehan Bloodline Talent, it's possible that the answer is different for Eldritch vs. Sorcerer-Priest magic.

I'm not sure where exactly, but it has been stated that you cannot gain T2 spells without first having at least 1 T1 spell. If you gain Rudementary Spell Casting, you gain a T1 spell. You can (at T2) learn T2 spells using Learn Spell (Ta) after this, needing to know at least one lower tier spell first, though if you take ASC/DSC you'd have to take the T1 version first.

I'm not sure exactly what you are saying here, but you technically can take Arcanum (Sorcery) at any time. Hell, it is useful to take for Arcanum: Sense Magic skill. As such, you don't need a 'prerequisite' to take ranks in it. From what I know, an Elorii can take ranks in it, though if they do it'll be a wasted skill talent since it doesn't work with Elder Sorcery.

From the text they don't have to be one of the normal 'unnatural' creatures, but you do need their blood on hand to ward against them, and it would only work against that individual.

I'm asking not about the Arcanum skill but satisfying prerequisites for the Arcane Spell Casting talent.

In the Official FAQ Version 4.3, p.5, second question on the right column, the answer mentions gaining access to the Arcane Spell Casting or Divine Spell Casting talent via a Background, Path, or Archetype "without needing to meet the requirements." Does this answer mean that these Paths (e.g., Initiate Itinerant, Templar Itinerant), Backgrounds (e.g., Initiate of the Gods, Templar), etc. bypass the Spell Casting talents' listed prerequisites of Prestidigitation and skill ranks?

I had originally interpreted these Backgrounds and Paths as simply removing the [Limited] constraint for the spell casting talents yet still leaving intact the other prerequisites. Does granting access to the talent remove the prerequisites as the FAQ answer implies?