In regards to why Eva sings "Suitcase": To be able to film on location, the film's producers had to agree to make the Eva in the film a bit more likeable than how she is typically portrayed on stage (a power-hungry bitch). So, to aid in the softer image, they trimmed the misstress character and gave Eva a sad "feel pity for me" song. It's only sung by the Misstress in the stage show to give the Eva actress a break for some breathing time and a costume change. In film, it also makes for a smoother transition from a little 15-year-old girl coming to the big city ("Buenos Aires") to the whore in "Goodnight and Thank You." On stage, it's actually more true to reality with the sudden Magaldi-dump, but the film had to sugarcoat.
The sugarcoating also explains this change:
STAGE VERSION:
EVA: Just listen to that! The voices of Argentina! We are adored; we are loved!
OFFICER: Statesmanship is more than entertaining peasents.
EVA: We shall see, little man!
FILM VERSION:
EVA: Just listen to that! The voices of Argentina! We are adored; we are loved!
OFFICER: Statesmanship is more than entertaing peasents.
EVA'S MOTHER: We shall see, little man.
Also:
STAGE VERSION:
ARISTOCRATIC MAN: Things have reached a pretty pass, when someone pretty lower-class, graceless and vulgar, uninspired, can be accapted and admired.
EVA: But your despicable class is dead! Look who they are calling for now!
FILM VERSION:
ARISTOCRATS: (same as Man)
ARISTOCRATIC WOMAN: But our privelaged class is dead. Look who they are calling for now.
okay, long post. Gonna shut up now.
-- SDG