Aye I would have scurried to the theater if it had the original characters.

I had hoped that maybe they would come back with some adventure where they somehow get to see Will or maybe Jack gets himself into another predicament where he needs Elizabeth and the Dutchman's help, and then she and Will would be able to see each other again

I agree with you about Jack as well.
Also, couldn't they have come up with something better than the Fountain of Youth? The quest for the Fountain of Youth has been around and done enough already...