I prefer the changes for the reasons you cited. I feel she is cut off and the lyric almost becomes a murmuring. She is entranced, delusional, "a sleep walker" as Joe calls her. If she sings the original line it definitely makes her sound more lucid in my opinion. At the end of the song she wanders off still in her dream. If she makes a declarative statement about being a star, then she is the fierce headstrong Norma and not the fragile faded star. Just my opinion.
"The sexual energy between the mother and son really concerns me!"-random woman behind me at Next to Normal
"I want to meet him after and bang him!"-random woman who exposed her breasts at Rock of Ages, referring to James Carpinello