Nope. Who is at fault are those who decided to pick up weapons and strap on suicide vests. The question is how to best mitigate those. I don't really see that "race" factors into it though.
It'd be nice, but a world free of terrorism is unlikely. If the relevant state vigilance is weak results of this kind are inevitable.
It is unlikely in any case. I'm especially wary of unchecked immigration. Now, don't get me wrong, I'm an immigrant myself and have counted amongst my friends people from many races, cultures and religions and celebrate many of the things that exist in my life because of it. Assimilation is key though and France especially has allowed enclaves to develop where ideals that run counter to the ethos of western secularism have been allowed to build. Any realistic level of vigilance less than panopticon-levels will have trouble with that.
I subscribe everything you said. The real solution would be eradicating relics which should be consigned to the dustbin of history: namely fanaticism and religion (any religion) through reason, but this is my very own point of view and far less likely.