User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-168.169.25.92-20151003163142/@comment-70.91.92.65-20151003192646

2 the salt's lot was a god weapon, so he couldn't repair it

3. they would get better(eventually)

7. yes the knife could kill him (but it must be in a vital area)

31.both souls then share the same body (but the cured soul is in control)

33. they could supress the magic of angels

47. yes the knife could kill both of them

49. crowley became the king of hell(he dipped into the pot as he said)

53. castiel would had gone back to heaven