Caroline
I wouldn't blame him if he was. The demon needs to die, and if the kid dies with it, well that's terrible but one life is not more important than hundreds.
I would guess they did, if they filtered you out.
They, well, Jeremy Gilbert, wanted to find another way because apparently killing Klaus would kill Gilbert's girlfriend too? But the trapping him in the ocean plan was his suggestion. Messing with his brain was another one, but from Jacen.