The Pew numbers are interesting, and sobering. I have no basis on which to contradict them.
As a general matter, I would expect that hard-liners would be less interested than moderates in emigrating to a West they see as hopelessly decadent. Certainly, if they want to live in a country where Sharia is the law of the land, that's not going to happen here, or even in France. So I expect there's a substantial amount of self-selection going on already.
That said, I'm sure there is a clash of values in some cases. I recall reading about a woman walking her dog in NYC -- she happened to go past a mosque, and was accosted by one of its members (dogs are "unclean", apparently). I certainly think it should be impressed upon the members of the mosque that they have no right to control who uses a public sidewalk, and that walking one's dog is perfectly legal. They've come from a very uniform society into a very pluralistic one, and they're just going to have to get used to it.
I think such clashes are of the same kind as other debates about the degree to which adherents of a religion may impose their views on others: debates over abortion rights, state-sponsored prayer in public schools, religious displays on public property, Israelis settling in the occupied territories because they believe God gave them the land, etc. etc. I think it's important to keep in mind that it isn't just Muslims who try to do this.
Anyway, in principle I have no problem with interviewing applicants for immigration (and/or their friends and relatives) to estimate their predisposition to violence, and rejecting individuals who seem so disposed. In practice, I admit, that sounds like a hard thing to do well. But I think it would be better for us to try such an individualized approach than to impose blanket restrictions on entire religious/ethnic groups.
Interesting that you should bring up Brendan Eich. I originally signed an online petition calling for his ouster, and then as I read more about the situation, came to regret doing so. Not because there was any indication that he'd changed his views, nor because I came to see the pro-Prop. 8 campaign as anything but one vicious calumny after another, but because he had made a credible pledge not to let his views affect his treatment of Mozilla employees, and a considerable majority (though admittedly not 100%) of those employees believed he would live up to it. Certainly, had he stayed on as CEO, and failed to live up to his pledge, he could have been ousted with much better reason and less debate. I now think he should have had the chance. Instead, he was a lightning rod for a lot of pent-up anger that many, including me, had over the success of the Prop. 8 campaign and had not really had any target to direct it at.
> But these countries do far, far, worse, and our leaders don't condemn them?
Well, along with the risk of fanning the flames of anti-Muslim prejudice, there's also the fact that some of these regimes are, at least nominally and for the moment, our allies against Daesh, the self-styled Islamic State. However bad you think Saudi Arabia is, and I'm sure I agree, Daesh is much worse. I have not been paying attention to exactly what our leaders have and have not been saying about Daesh, but I'm not under the impression that they've spared the group any criticism.
I don't entirely disagree with you. But I think the situation the world is in is very delicate, and wise leaders will choose their words very, very carefully.
I also think it's important for us as individuals to resist identity-group politics. The better we all get at seeing people of other cultures as human beings -- however misguided some of their beliefs might seem to us -- the better the world's chance of navigating these perilous shoals.