you can't do too much personalization in the legal ceremony. i was told i could write my own vows (but didn't have to) and that i could add a sand ceremony or reading, but that i would have to provide someone else to read that because the judge would not.
at dreams cancun, all ceremonies are in english. i think other areas, as well as the judges specific resorts contract with, are different. most parts of mexico require the legal ceremony to be in spanish. your marriage application and actual certificate will be in spanish (so you'll be blindly signing your life away ... we were certain we had sold our kidneys or something, lol).
michelle, i'm sorry to report that our wedding DID have that whole bit about marriage being the only way to found a family. we giggled through most of it. especially the part about giving your children food. i mean, seriously? food? "food and love." i was just thankful that the ceremony wasn't extremely religious.
oh and yes, there was a ring exchange that the judge read, and had you repeat a phrase as you exchanged. i'd have to watch the video again to see what exactly it said, but it wasn't much beyond the usual, "i give you this ring as a token of my love."