A deadly threat is the best fit description of menaces in this context.
The word "gabelle" refers to a tax.
For example, during the 15th century, the French had a tax for salt.
If I'm correct in thinking the play is "Romeo and Juliet", then Mercutio is related by being a character in said play. Hope this helps.
While we wait for the sun to rise is a sentence fragment.
There is no ending that completes the sentence.
To finish, an example would be:
<em>While we wait for the sun to rise, we eat breakfast.
</em><em>
</em>