I read somewhere that Sam Goldwyn loved Blaine's stage performance and insisted that she play Adelaide in the film. I actually like her film performance, but I admit she is very Broadway in the movie.
I vaguely recall an interview Blaine did decades ago about "Pet Me, Poppa" replacing "Bushel and a Peck" -- something like the original song was perceived as being too overtly sexual -- she said the reason that was given was pretty dumb.