You have identified the key role of setting in this play. In A Midsummer Night's Dream, just like in As You Like It, the forest has a key function in terms of its setting, and works in opposition to the city of Athens. Athens in this play is considered to be the place of reason, rules, logic and order, which is contrasted brilliantly with the disorder, chaos and emotion seen in the woods. The woods is where everything goes topsy-turvy and result in some of the most amusing scenes of the play with Bottom having the head of an ass and the lovers falling in and out of love with each other like they were 13 year olds.
However, whilst the woods give us some of the most amusing scenes of the play, your very good question identifies that underneath the exterior of laughter something more serious and more disturbing is going on. What you need to think about is how the love potion exposes the lovers and confronts them with truths about their own qualities and the qualities of their object of affection.
Lysander at the beginning of the play again and again protests his loyalty to Hermia in rather cliched terms, yet his constant "love" for Hermia is shown to be rather shallow - he quickly deserts her for his pursuit of Helena and engages in a series of insults where he makes clear his hatred of Hermia. His real character is exposed and Hermia can see who she really loves. Also, Hermia is now put in the position of her friend Helena, seeing the man she loves now pursue someone else. She experiences the same loss and pain that we see Helena exhibiting in Act I scene 1. Demetrius suddenly re-loves Helena, and Helena gets exactly what she wanted, yet oddly is not happy with this and cannot believe it, and lastly the friendship of the two women is ripped apart as Hermia responds to the situation with anger - not at the men but at her former "bosom friend".
This is essentialy what is disturbing about the woods - what happens, although funny for the audience, makes the characters confront who they really are and we see how superficial they can be, and above all we see how pathetic we are as a species when under the spell of love.