I have to admit that I forgot about the public wedding Michael and Applie had. It's a bit surprising that Michael would take such an enormous risk given his penchant for secrecy and calculating manner that we later see.
I never realized the point Turnbull mentioned re: Kay and Vito never appeared together in in the film accept in the family photo. Thanks for the details, Turnbull!
Dontomassino was a conduit to the Corleones in NY, after all he brought Michael the news about Sonny's death, and later had to play a role in engineering things to get him out of Sicily and on his way back to the US. So I assume the family knew Michael
was marrying a Sicilian girl, who I am sure Dontomassino had checked out, and I believe they would have approved.
As for the public wedding, we have to assume it was thrown by her family, who may or may not have been "connected" thmselves.
I would imagine Dontomassino made serious security arrangements.
Finally as for TB's insight that we only see Kay and Vito together for the photo probably shows that Vito didnt fully approve of this American girlfriend. Its odd in a way because Vito wanted him to be Senator Corleone, and a WASP wife would have been a political asset. I think eventually he resigns hmself to the marriage, and toward the end he asks Michael if he's happy with his wife, almost as if to say, "Ok, if she makes you happy then I am happy for you."
