Stop it! That tickles! :P
1. Am I right that in scenario 1 if standing next to the open door on tile 1, you're in LOS of an enemy on every single hex in tile 2? Seems very odd but it's possible to draw a line to one corner of the hex so....
2. Is there any way to stop a stun or other status from an attack? If they draw a miss attack modifier or I negate damage by losing a card for example?
No if they draw a miss, the condition still happens.
3. For a monster attack modifier which does "attack +0, strengthen" does the strengthen effect happen after the attack?
It happens in the order it appears. So the attack happens, then strengthen.