I personally doubt that they knew about it. However, I also doubt they would have cared about the presence of French nationals if they were aware and cool with such a project

Oh I wouldn't go as far as saying the French knew what would happen to the plane, but that they planned for an escalation of violence seems quite evident

Oh they knew the coup against Tutsi power was about to be violent. It started with the assassination of the president by having his plane crash, they weren't planning for a peaceful transition of power

In Africa, English and French are mostly second languages used in order for different ethnic groups to communicate with each other

Hutu and Tutsi are not ethnicities only dependent on their second language, it is an ethnic and class division supported by the Belgians. Divide et impera, classic stuff

This situation also exists in Nigeria, where again the Francosphere and Anglosphere interests clashed during the Biafra war.

And uhh, maybe I should talk to you about Canada, Belgium, Spain, China, India, Ukraine, and countless other countries that practice bilingualism or even multilingualism

It was most definitely the government. François Mitterrand at the time was convinced (like lots of French people tbh) that the French language was going to fade everywhere to English, and that the francophone community of nations was, sort of, under siege by English.

He made it clear he supported the francophone side for this reason. Did he know what they planned to do? Hard to say, probably not, at least for the genocide, but the French government was most definitely in cahoots with them. And the French government very well knew about the planned coup. Not some private actor.

Except force doesn't necessarily stop anything. It can make things much worse. There have been multiple foreign interventions made to pacify and separate the two sides of African ethnic conflicts and that rarely ends up with great results. Last one was in the CAR between the Seleka and the Anti Balaka

Edit : typo,it's the CAR not the BAR

Roger de Hauteville, but not a crusader