So while the main plot line is now solved, what remains are just a couple key points with the Fairy King.
In chapter 2:
1) He simultaneously lays out the stipulation that there is a time limit to complete her wish in, but also gives implication that if she completes it that she might...not die again?
The only reason I can think for him asking this question is thinking that she'd solve it sooner than the time limit. There wouldn't be a reason to ask if she were to need all ten days, only to die once more regardless of fulfilling the wish or not.
2) This line he uses before Ophelia puts the crown back into its box and shuts him away.
If this were another series you could conclude that it was a bluff to remain out of the box; but the plot here has been built up entirely on lines and actions being said and done deliberately, so I'm very apprehensive to dismiss it.