I hope 13 is not an unlucky number for Q&As!

Five leagues questions:

Is there an exact list of what enemy abilities count as magic?

The special abilities of the following characters are considered magical: Corrupt Sorcerer, Deranged cultist, Scheming heretic, Craven hex-chanter. 

From the enemy tables the following special abilities are considered magical: Coven of the half-dead, The ascended, War cultists, 

From the expansion: Blood-stench rituals, Wind swept wanderers, Forgotten dead.

You'll notice a few abilities that feel magical in nature but which are not included (usually things to do with fey things or aberrations). 

Exactly when is the reroll from the Guidance spell used?

You must choose to reroll immediately after rolling for one of the rolls listed (hit, proficiency, enemy armour). You cannot wait to see what the effects of any additional rolls turn out to be. 

What counts as targeting for the Fey Reaver special ability?

Any spell that requires sight and any ranged weapon.

How does the Legion of the Swine ability work?

Its a penalty for them, not a bonus. Their crossbow legionaries don't count as nearby troops for other legionaries (but a crossbow legionary can RECEIVE a combat bonus from a nearby ally that is a melee soldier). 

Leagues AND Parsecs questions:

What happens if a modifier makes me roll over 100 or below 01 on the injury table (or another table for that matter)?

Just treat it as the highest / lowest entry on the table. 

Leagues Lore questions:

What exactly does a Congealed strand look like?

A small pellet of some sort of elemental force. Could be gleaming sunlight, a spark of fire, an orb of water and so forth. It can be carried and handled (carefully) but if treated roughly it breaks into its component form. 

Are the Faceless Kingdom humans? 

I intended them to be. Yours may not be.

Were the Faceless Kingdom inspired by the Granbretan?

Not intentionally but I did enjoy the Hawkmoon novels so maybe unconsciously?

Are the Spider-Touched on the Ice-Heart Court list fey?

No, they don't have the Fey trait and are not faeries or goblins. They are forest dwellers who worship spiders and act as agents of the Fey Queen in order to obtain favours or power. They are meant to be humans but you could make them other creatures if you like and have some cool models.