rules for big items and not paying attention

[joshman]

three questions here:

1.
what happens if you trade a big item with a player that already has a big item?
Is the trade negated because they cannot carry two or do they have to resolve the too many big items rule because they were not paying attention.

2.
What happens when you play a big item but already had one in play and you were not paying attention? Can you pick up the big item that you just put down? or do you then have to resolve the too many big items?

3.
When resolving the too many big items and you try to give a big item to the player with the lowest level, if they do not want it can they refuse to take it?