Grandstanding is a big part of politics
Making outrageous or impossible demands is a time-honored way to curry favor with the public. Pick some issue near and dear to their hearts, take a hard line on it, and be as loud about it as you possibly can.
Your demand will, of course, be ignored. But that almost doesn't even matter.
It helps your negotiating ...
TL;DR: They mainly want Macron to apologise, and to stop targeting Islam/Muslims in the name of freedom of speech.
I am a resident of the 4th largest Muslim country. Although our government is silent about this issue, there are big rallies and widespread boycotts going on everywhere. People are participating en masse for we_love_mohammad_ﷺ_challenge on ...
Yes, there have.
Here's one, sorry, in French.
Basically, at least in France, they are losers, in the literal sense of the word. Poor, poorly educated, young and often recruited while in prison for minor non-terrorist crimes.
Here's the abstract:
This study, based on original judicial sources, assesses the profiles of 137 individuals sentenced ...