Listed below are six essay prompts: create a 400-600 word essay. Be sure your essay follows the MLA style of formatting. 1. How are specific physical symbols used to characterize the essential nature of Stanley Kowalski? 2. Characterize the essential differences between the Kowalski and the DuBois worlds. 3. Using evidence from the play, try to determine which is the real Blanche--the innocent and charming Blanche or the degenerate and promiscuous Blanche. 4. Show how each subsequent meeting between Blanche and Stanley increases in violence and antagonism. 5. In spite of Blanche's past life, her deceit, and her artificiality, most readers and viewers tend to sympathize with and align themselves with her. How can this emotional reaction (or attachment) toward Blanche be justified? 6. Show how a Mitch-Blanche marriage could have been a perfect marriage if Stanley had not interfered.

On your point 3, I would argue that in viewing Blanche, to use words such as "degenerate" and "promiscuous" is somewhat unhelpful. The value judgments attached to such terms in her case, I believe, are unrealistic and unfair. But an awareness of what I would consider a problem with the way the question is worded can lead to an answer to the "deeper" question that lies behind Blanche's personality and that of Stanley, and of Stella, as well.
Like every real person, the characters in Streetcar are a mixture of different qualities, both "good" and "bad." Even Stanley, though the emphasis is on his crudeness and abusiveness shown in his physically violent behavior, appears to love Stella in his way. The Kowalskis are a working-class couple, removed from the rarefied world Stella and Blanche originally are from. Blanche is, in fact, charming and sensitive. Her love for her husband, whom she discovered to be gay, was genuine, and the shock of finding this out about him and his subsequent suicide threw her life off course. A reader, especially in our time, who does not sympathize with her would have to be extremely cold-hearted and unforgiving, in my opinion.
It is not surprising that the antagonism between Blanche and Stanley should increase as the play progresses and they continue to interact with each other, given that the two of them are not "on the same page" to begin with. Whether she and Mitch could have had a successful marriage is anyone's guess. Mitch is a blue-collar person like Stanley, but without the latter's cruelty. Though he and Blanche come from different social backgrounds, such a difference is not always an impediment to a successful pairing in real life, so it's possible that these two could have been successful as well had not Stanley destroyed it for both of them.