[VOA]

They also happen to be really lousy "Muslims." They never read the Qu'ran.

That's really the point.
It's the Muslims that actually read and believe the Koran
and the Hadiths...
and then "put their faith into action" that are a danger.

Lapsed and/or apostate Muslims are generally not a problem.
Of course, a few of them get killed before they can escape to havens.
Like the USA.

[Question_Assumptions]

It's possible to read the Koran but treat the Hadiths and such will less authority. The Libertarian Muslim friend I have will observe Ramadan and such but he has a much less restrictive interpretation of what's halal, his son isn't circumcised, and his wife doesn't wear a head scarf. When I've asked him about it, his answer is, "That's not really in the Koran." That suggests to me that it's possible to be a much more Western-friendly and flexible Muslim than the militant Muslims would claim. But that's not really all that surprising since Fundamentalist Christians also have a much narrower idea of what it means to be a Christian than many other Christians do.