1) Can Karl fire with Doom across the doors? If a grenade can pass (just one circle ok, but pass) and a grenade isn't able to open a door, maybe a mystic bullet (that ignore bulletproof jacket, 'couse mentally guided to dodge bulletproof jacket) can?

2) A grenade thrown in the circle near a door, does it hit a character behind the door?

Thanks.

Grenade "explosions" hit all adjacent spaces, so yes, even the other side of a door.

Karl's bullets also go through doors, they move just like a character does.

That's right, thanks.