A few mistakes:
While it’s commonly believed that the first capitulations date back from 1536, during the embassy of La Forêt, it is not true. The first capitulations were given by Selim II in 1569 to du Bourg (see https://www.college-de-france.fr/media/gilles-veinstein/UPL35525_Gilles_Veinstein_cours_0708.pdf p.698)
Also, in the Echelles themselves, the French usually got their asses whooped by the Dutch, the English and even the Venetians who were bringing better wares from the West at a better price. The true big business of the Frenchies was in transportation, in what was known as the maritime caravan (https://books.google.fr/books/about/La_Caravane_maritime.html?id=EJbfAAAAMAAJ&redir_esc=y). The Marseillais merchants used habitually Maronite dragomans (translators/advisors) and entire families became specialized in the translation business and numerous children becoming “jeunes de langue” on the Venetian model. It’s worth remembering too that the Lebanese came to Europe in large numbers and that there was a healthy Maronite community in Marseille from the 17th century onward.
What’s more, it is pretty disingenuine to separate the 1860s from the Colonisation per-se. The late 19th century can safely be considered as a prelude to colonisation with the Western powers and grouped with the post-1918 period into a single whole as the Ottoman sovereignty over the Arab regions was becoming increasingly theoretical and the meddling of the French in Beirut and the Mountains was becoming heavier every year.
Finally, it is probable (I don’t have numbers, it’s just a hunch) that if French was used in some elite and commercial circles in Lebanon, the colonisation (and the post 1945 meddling) increased the use of the language in the population both in Syria and Lebanon. There’s a quantitative arguments (going from 10s to 1000s) and there’s a qualitative one (99% of French speakers before 1918 were probably Maronites or Jews, after all the groups began to speak the language of Molière to some extent)