I have some questions, plz help

1) when should I apply the power of Leoric in the damage calculation ? The rulebook says the attack and defense are simultaneous

TEXT: the power said"each monster within 3 spaces of you receive -1heart on all attacks rolls( to a minimum of one)

Example: 4 hearts of damage in the roll

the oponent give 3 shields in the roll

4 damage -1(leoric)=3 - 3 shields = 0 damage

or

4 damage - 3 shields = 1 - 1 (leoric) = 1 because the power is to a minimum of one

2) In the quest the cardinal's plight in the encounter 2(pag 9)

A) Can i use the power of zombie disease in the cardinal Koth? will he lose 1 hp because he don't have stamina?

B) In the quest say "locked door to the library cannot be opened until the heroes find the rune key" and after "when a hero first open the door to the library read the following aloud."

have the hero that got the rune key need be the hero that open the door???

I would say the -1 is applied on the actual attack dice. If the monster rolls 4 hearts then -1 is taken right off of that before comparing it to amount of shields rolled.

but is impossible get bellow 1 damage if the roll use 2 dice. put the final text of the power a little no sense.

TEXT: each monster within 3 spaces of you receive -1heart on all attacks rolls ( to a minimum of one)

I think Blue + Yellow dice can net you a single heart (just a surge on yellow), which would go down to 0 if not for the minimum of one text.

There are some attack dice faces that have zero hearts, providing only range or surges to the roll, therefore it is possible (at least with some weapons) to roll only one heart on multiple dice. Leoric's penalty is applied to the attack result before defense dice are considered.

Regarding the Cardinal's Plight questions, I believe there are some errata in the FAQ that might help clarify things.

The hero who opens the door may not need to be the one who found the key.

It is a magical key, which works like a remote control device - one does not stick the key in a keyhole.