About your first point, you are totally right. A report made in France tells that 28% of Muslim support an authoritarian position and a separatism against their host country society. While 1/3 is technically a minority, it is still a really hight proportion and a really signifiant number of people that can be counted in millions.

"28 % des musulmans de France peuvent être regroupés dans ce groupe qui mélange à la fois des attitudes autoritaires et d’autres que l’on pourrait qualifier de « sécessionnistes ». L’islam est un moyen pour eux de s’affirmer en marge de la société française." [28% of muslim living in France can be grouped in this group that mix both authoritarian and « separatist » attitudes. Islam is for them a way to affirm themselves at the edge of the French society.] Un Islam de France est Possible, Institut Montaigne / Hakim El Karoui, 2016.