Troubled communities? I'll say! The "communities" in both Macbeth and Romeo and Juliet are "troubled" because of different forms of conflict.
Let's take Macbeth first. The reason Macbeth is named the Thane of Cawdor is because of his achievement in battle. Any country that is at war is going to have a troubled community. This is certainly the case. And this is at the beginning of the play even before Macbeth is plagued with his "vaulting ambition"! Think of how it changes to become even MORE of a troubled community. Witches are lurking with declarations of evil. "Thou shalt be king hereafter." And possibly due to the evil presence of the supernatural, Macbeth does act on his tragic flaw of ambition and murder Duncan.
Life's but a walking shadow; a poor player,
That struts and frets his hour upon the stage,
And then is heard no more: it is a tale
Told by an idiot, full of sound and fury,
Consider Lady Macbeth's involvement, and a conspiracy is involved! Luckily, though, we end up with a good and mighty king at the end, so as with some of Shakespeare's tragedies, it ends with a hint of hope.
Romeo and Juliet also live in the troubled community of Verona: troubled with the family feud between the Montagues and the Capulets. I have to say that the 90s version of the Romeo & Juliet movie (portraying the two families as two rival gangs, with them using guns called "rapiers" as weapons) does a FANTASTIC job of reflecting the troubled community. In the play itself, there is no doubt of the feud. It is why Romeo and Juliet are truly "star-crossed lovers" due to the former being a Montague and the latter being a Capulet. Juliet says:
My only love sprung from my only hate!
Too early seen unknown, and known too late!
Prodigious birth of love it is to me,
That I must love a loathed enemy
The feud is the reason for their deaths (as long as you don't fault them for their own suicides). Still, again, because of the lovers' deaths, the feud ends at the end of the play, so it ends with that vision of hope in the face of tragedy.