I heard back from Nayeli. Aurora must be gone. Nayeli answered pretty quickly. As far as planning, it's my understanding that about 2 months out you will receive a giant packet to fill out and return. That's when all the big decision making happens. The only things I know for sure at this point are that we have the chapel reserved and the 5pm time slot for the ceremony.
Through another forum here on BDW, I found Alejandro Monroy to perform the ceremony from cancunminister.com. What we loved about him is that you get BOTH a legal and symbolic ceremony in one. The judge is there with the paperwork, etc, but Sr. Monroy runs the show and does a religious ceremony. Obviously it's not cheap because you end up paying for the bloodwork + judge through the hotel and then his fee + the resort fee for an off-resort individual, but we're really happy to have everything done in one swoop.
Regarding the cake, I figure we won't have much control over what it looks like so we've decided to go with an awesome customized topper from Etsy.com (the store is called clayphory). I did, however, tell my MOH that the only request I'm making for my bridal shower is a nice cake!