'Night, Mother

Yes, "Will Jesse kill herself?" is definitely a major dramatic question that would work for 'Night, Mother.  However, I believe that there are stronger options.  I would suggest that a better alternative major dramatic question would be, "Will Jesse find reason to live?"  If Jesse's only goal in this play were to kill herself, none of the action that occurs throughout the play would be necessary.  However, the argument could be made that Jesse doesn't just simply kill herself right away because there is something that just needs from Mama. This is what drives the central action of the play. In this way, this story becomes more about the struggle to survive than about giving up on life.

There's a reason that Norman chose to have Jesse spending the night with Mama before killing herself. This is not to say that I believe that Jesse is desperately fighting for her life, because I don't think that.  However, Mama is trying desperately throughout the entire play to stop Jesse from committing suicide. She is relentless, and employs many different tactics in an attempt to take control of the situation. To me, this leaves the audience questioning whether or not she will be able to save Jesse's life. Will Mama be able to "take control?" Will Jesse realize that suicide is not best alternative? These are the questions that drive the action of this play, and I believe that "Will Jesse find reason to live?" is a strong MDQ for it.

Trifles

I do not believe that an ultra "stripped-down" production of Trifles would be particularly effective.  It is Mrs. Peters and Mrs. Hale's attention to seemingly minute detail that unfolds the plot of this play.  The specificity of the text is also something that I believe would only work in a setting containing high attention to detail.  The script distinctly points out the dead bird, the bird cage, the unfinished quilt with a log cabin on it, etc.  The detail contained within this world would not be complimented by a bare, minimalistic set.  The text contained within the play just does not support it.

However, I could understand the argument for a minimalistic set being made for a few reasons worth considering.  One such example would be in order to give the play a sense of timelessness.  By creating a space that is essentially a void allows you to take the action of the play outside of any particular time period, at least to some degree.  It gives you the opportunity to bring the plot into a possibly modern-day setting.  It also can relay the message that the problems in this play are not specific to a particular time frame.

Overtones

In Overtones, Alice Gerstenberg makes it pointedly clear that Hettie and Maggie do indeed address each other.  Many times throughout the script, the stage direction informs us that Hetty and Maggie are speaking to one another.  So, I think that it's safe to assume that they are at the very least speaking to one another.

However, I don't necessarily believe that they are "communicating" with each other.  From my interpretation of the play, Hetty and Maggie cannot be heard by anyone other than Harriett and Margaret, respectively.  How could they be?  If these characters represent the "inner-selves" of Harriett and Margaret, then how could anyone else possibly hear what they are saying?

I believe, rather, that these characters are representative of the "overtones" that are existent in the dialogue exchange between Harriett and Margaret.  It's almost as though everything that they say exists somewhere deep within everything that Harriett and Margaret say. 

That being, said I suppose this isn't the only way that this script could be analyzed.  I don't think it would be ridiculous for someone to make the production choice of having Hetty and Maggie very clearly communicating and interacting with each other, so long as the reasoning behind it was solid.  There's nothing in the script, at least to me, that would absolutely prohibit someone from staging this play one way or the other.