Rules questions after first play

I have just played my first game with my two children, and we all enjoyed the game very much. I especially like the physical design elements—the way the box became the board, and the manner in which all the pieces fit together. Whomever worked on designing and constructing this must have had a lot of fun! The sculpts are also quite nice, and I love the detail. We are looking forward to playing more, but there are some rules questions that came up during our game that we couldn't quite parse out on our on, and I haven't seen addressed elsewhere.

1. By default, victims do not roll any reaction dice—they only get to if a player gives them an object, correct? (Exceptions being Tom, who automatically has at least one success, and Kam, who always has at least one die.)
2. Only one object card may played per attack to assist a victim, correct? (Not one per player.)
3. Bob automatically ejects a monster after an attack. Zombies need two successes to be ejected. Which ability wins?
4. If a barricade is placed on a door slot where the door is not smashed, does it replace the door or go on top of it? (Meaning a player would need to first smash the barricade, then the door as two separate actions.)
5. There are eight Nocturnal Event cards in the stack, but nine hours in the game. Is the last round intended to not have an event active?

Thanks!