How were they menacing? Why does it matter how many teens were in the SUV?
How many weapons did they display?
Read Dunn's own statement above - there is no indication that any of them had, much less displayed, a weapon.
What are the sound and noise ordinances in Jacksonville?
Irrelevant. You can't use deadly force to enforce sound and noise ordinances.
What made Dunn so fearful of his life that he had to escape the danger?
I'm guessing that Dunn was a drunk idiot.
See post 68
Dunn was not looking for a fight.
He was scared for his life.
The teens in the SUV threatened to kill Dunn and used bad language.
He saw a shotgun.
Dunn was scared to be in Jacksonville and left the scene to protect himself, his girlfriend and to eat pizza and had to go back home to be with his dog and family.