How does Shakespeare present the family dynamic in Romeo and Juliet? For anyone that doesn't know, the family dynamic is how members of a...

From the most fundamental points of view, Shakespeare
depicts family dynamics as going well when children act like children and are obedient. 
As long as Romeo and Juliet follow the plans of their parents in terms of not straying
into the realm of "the other" and adhering to edicts and rules, no matter how arbitrary
or baseless, the parents are happy with their children.  The Montagues and the Capulets
reveal no dissatisfaction with their children at the outset of the play.  Lord and Lady
Montague might be concerned with why their son is so melancholy, but they do not feel
that he is a bad son or has dishonored the family.  The family dynamics become toxic
when the children break apart from the family and enter the realm of the forbidden
"other."  This is best seen in Juliet's home.  In Act III, Sc. 5, we get a glimpse of
how the family dynamics are actually constructed.  If Juliet agrees to marry Parris, all
is well.  Lord and Lady Capulet are happy with their daughter and could not find a
better one.  Yet, when she expresses her desire to not marry Parris, they cast her out. 
Lady Capulet "washes her hands" of her daughter, emotionally disowning her.  Lord
Capulet actually finishes what his wife started in literally disowning her to poverty
and a life where she does not have her family's support.  The dynamics of both families
are fine when their children are not questioning the rules of the household and are
obedient.  It is when they become critical thinkers, seeking to transform what is into
what can be, and going where their passions lead them do both children rightly see
themselves as outside the family system, renegades who will not be embraced by a family
dynamic that is predicated upon order and structure as opposed to life and vitality.  It
is only with the childrens' deaths do both sets of parents realize that their decisions
have been made without their respective families' interests at heart, setting the stage
for a more constructuve and healthy family dynamic.