en, 'from them
injure, 'insult.' So the adjective 'injurieux' generally means 'insulting' not 'injurious.'
1. 14. approchais de, E.B. 132. See another construction on p. 3, 1. 19.
1. 17. la porte Saint-Denis, a triumphal arch erected to commemorate the victories of Louis XIV. in the Netherlands. It stands in the north centre of Paris, on the inner circle of boulevards.
1. 20. que faisaient, order inverted because of the words qualifying des marchands, E.B. 12. But perhaps it would have been inverted in any case.