I had a bunch of questions, but think I managed to find the answers myself by scouring the rulebook. So instead of asking them here, I am going to post my findings and take the "correct me if i'm wrong" approach.

Clarification: "Battlefield" vs. "Battlefield Only"
"Battlefield" means that the power only takes effect if the card is in the battlefield zone
"Battlefield Only" means that the card may only be played into the battlefield, but has no bearing on whether or not the card's powers take effect if the card ends up being moved to another zone.
The same applies for the quest and kingdom zones.

Cards that cannot be targeted can still be affected by cards that do not specifically target them. For example, King Kazador can still be affected by Troll Vomit.

Since the apply damage phase is not broken down on a per unit basis, damage is applied simotaneously. This means that if 3 Dwarf Rangers in the quest zone are eliminated, a total of 2+2+2 (not 2+1+0) damage is dealt to target units or capitals (friend or foe).

Clarification: "This Zone" vs. "This Corresponding Zone"
"This Zone" refers to the zone a card is in for a single player only.
"This Corresponding Zone" refers to the same zone the card is in for all players.
Thus, your Rune Of Fortitude only hinders enemies attacking you, it does not hinder your ability to attack them in the same zone.

On Johannes Broheim, "end of each phase" includes your opponents phases as well

"After your turn begins" means "After your turn begins, but before the kingdom phase" (for example, Shrine to Taal)

When being attacked by a unit with Horrific Mutation attached, you would not want to declare anyone with only one hit point left as a defender, it would immediately die (per page 7, card anatomy key, bullet 7).

Bloodthirster. All damage cannot be cancelled while this is in play, not just that applied by the bloodthirster (see page 15, constant effects). If the Bloodthirster is the only unit left in a zone, it must sacrafice itself.

Looks good.

One thing about King Kazador, you must pay the 3 resources for the Troll Vomit to kill him.

Actually, no, Kazador's ability does not kick in with Troll Vomit since he is not specifically targeted. The "playfield" is the target, in a manner of speaking.

You do NOT have to pay extra to destroy the king. He is not "targetted"

"Since the apply damage phase is not broken down on a per unit basis, damage is applied simotaneously. This means that if 3 Dwarf Rangers in the quest zone are eliminated, a total of 2+2+2 (not 2+1+0) damage is dealt to target units or capitals (friend or foe)."

My understanding would be that NONE of the 3 Rangers' abilities would be triggered if all 3 were destroyed simultaneously, and so no damage would be dealt. A Ranger would need to be alive to be able to have its ability triggered by the death of the other rangers, and they are also not triggered by their own deaths.

I am not 100% certain of this, but Im sure a rules clarification has been posted before. Please correct me if I am wrong, but a dead ranger shouldnt get to use its ability.

Couldn't you say that all units are targeted by Troll Vomit?

you could, but you would be wrong in the context of this game. The word "target" is not on the Troll Vomit card, so no unit is targetted.

Evil Mushroom said:

I think this is true for continuous effects.

However, I think it's slightly incorrect. For activated effects, "Battlefield" means that the effect can only be played if the card is in the battlefield zone. The difference is this: if the card moves zone and isn't in the required zone when the effect resolves, the effect still works.

mateooo said:

True.

By the way, Magic has the exact same wording. For example a card with protection from white (can't be targeted by white cards) is still destroyed by the card Wrath of God (Troll Vomit as a white card)