Emotion, Drama, and Deceit

I've been thinking about Nothing in Shakespeare again, and made the claim that the use of this and related words (something, everything, thing, etc.) figures into a preoccupation Shakespeare has with aspects of life whose existence is in a certain sense questionable, giving as examples of those aspects -- emotions, theatrical drama and deceits. Question: in what sense may the existence of those aspects be called questionable?   

Emotion. Emotion isn't constant, palpable, so do we know it was ever there? If you grieve only a little while before your remarriage, was your grief something or was it nothing?  If you "love eternally" one person then "love eternally" another was that love something or nothing?

Drama. The theater is real in the sense that the stage and the actors are certainly real, as are the feelings that the actors inspire in the audience. And yet that isn't a person really loving or dying on the stage. The drama comes from something (actors) and creates something (a feeling in the audience) but is itself nothing (only the appearance of a thing.)

Deceit. Deceits and lies certainly exist as statements of a kind, but are statements that create false ideas: an idea that something that never was, was -- that nothing was something.

There are other aspects in this vein. Just thinking of All's Well -- there is boasting, in which one claims to be things one is not (Parolles) and there is being something in title only (Helena is only the shadow of a wife, the "name and not the thing.")  Also obviously in this category -- dreams.