When placed upon a wand, do the effects of a Sarish [Blessed] rune (from Forged in Magic, Vol. II, p.12) and a Sorcery (Eldritch) rune (from Forged in Magic, Vol. I, p.10) stack?

If not, the effects of the Sorcery (Eldritch) seem to entirely trump the Sarish [Blessed] rune to make the later obsolete.

In ARPG p. 330, the Monstrous Flaw Thrice-Bound mentions the Demonology Tradition. Should that be the Diabolism Tradition?

Several val'Mehan Bloodline Talents (e.g., Sarish Is Known to His Chosen and Master of the Arcanum: see ARPG pp.222-23) grant the val the ability to cast one or more magic spells. For these spells, is the val'Mehan's Primary Attribute Logic (as per standard Eldritch Sorcery) or Charisma (as per Sarishan Sorcerer-Priests)?

Given the Valinoric source of the val'Mehan Bloodline Talents, I infer that it's probably Charisma (as per Sarishan Sorcerer-Priests), but I don't see any explicit answer in the rulebook.

Three questions about ranged attacks and ranges:

1. ARPG gives rules for Ranged Weapons, but thrown Melee Weapons seem less clear. In ARPG p. 233, Table 2-24 lists separate "Range Increments" and "Max. Range" for each ranged weapon, and p. 238 gives the rules for range. With a Melee Weapon with the Thrown quality (ARPG, p.240), is the listed range the increment or the maximum? If it is the increment, then what is the maximum range for those weapons?

2. For a javelin, Table 2-24 (p. 233) lists the range increment listed as 20' and max range 60', whereas the weapon description on p. 243 lists the Thrown quality with 30' range. Which is correct?

3. Some Weapon Tricks (e.g., Darken the Sky and Twin Throw) list a range that is greater than the base range increment of the weapon. I presume that's all weapon trick ranges are the maximum possible range at which the trick can be applied, right? Does the penalty for going beyond one range increment still apply when using these tricks?

Per the Errata/FAQ v4.3, it must be a Tier 1 spell.

My read is no, it does not count for any prereqs. It simply allows you to cast certain spells without having the Arcanum spell.

ASC and DSC are Limited Talents, which means that normal people cannot take them willy nilly. The paths and Background that you listed make DSC no longer limited to you. However, it does not grant you the talent, which means you still need to acquire the talent as per normal. The same is true with other Limited talents such as Saluwe's Embrace or Loyal Companion. While a val'Mehan can gain a Loyal companion infernal, it doesn't mean they can ignore the prereqs needed to 'upgrade' that infernal with the Loyal Companion talent.

If it only lists a single range, that is it's maximum range and there are no incriments. Basically, you can throw a dagger 30' without a die penalty, but you can't throw it any further than that.

That is referring to Backgrounds, Paths, and Archetypes that explicitly grant Arcane/Divine Spell Casting as part of the "thing" (not ones like those you mention that simply grant access). Your original interpretation was correct - those simply remove the [Limited].

No. They are both static bonuses from the magic item category so don't stack (see stacking rules in FAQ v4.3 pg 12).