Couple of unaware details .

[Mr_Draco]

For question two, you are correct. That player has to be the target of the curse, either from kicking down the door or another player specifically targeting them. If they are the side effect of a curse (like the player to the left/right of the player that was cursed), then they can not cancel the curse or avoid it.

Brf covered everything else. If you want to house rule a limit on unequipped items and small items go ahead but I think most of us play via the rules which is no limit.