After I got over the excitement of the teaser I started having concerns about how they would pull this off (Palpatine returning that is). The I saw an interview of John Boyega, where he said as soon as read that Palpatine was coming back he went to JJ and said that Palpatine coming back doesn't work. JJ laid it all out for John, and John was okay with it. Not that's really groundbreaking or anything. But John is pretty hardcore nerd, and I have a feeling he had some of the same concerns others in fandom have.
Also just knowing that they've been trying to implement Palpatine returning since TFA, means they've had long time to develop this. So that's comforting.
This makes me feel a little better now