What if those things are not faults?
Sure, there's some theoretical possibility that the Islamic God truly exists and is the one and only God. There's some possibility that Mohammed's Quran and Islam's traditions are the final and binding revelations from God. And it's possible that what Islam says that God commands is precisely what God commands.
I don't believe that those things are true though. And this thread is ostensibly about what people think about Islam.
What if they are evolutionary advantages? What if they are advantageous for survival?
That might be great for the belief itself, provided that the ability of beliefs to perpetuate themselves down through time is defined as 'evolutionary advantage'. It probably wouldn't be nearly so great for the people that hold the beliefs.
This kind of model suggests that the most aggressive and intolerant belief might be the 'fittest' belief, because it will drive all other ideas out of contention (if only by motivating those who hold the least tolerant belief to kill proponents of all rival beliefs), and because it will be the most resistant to subsequent modification as conditions change.
(Somehow, I'm reminded of Hitler and his Nazis. His views didn't turn out to be nearly as 'fit' as he assumed they were. There's danger in attacking everyone around you, since it forces everyone else to become your enemy.)
Where is there any evidence or reason to believe that living by a humanist, liberal outlook is sustainable, viable in the long run (for individuals as well as whole societies)?
Well, sustainability long-term seems to imply some ability to adapt as conditions change. That's what drives biological evolution.
If modern transportation and communications have thrown people from all around the planet into close proximity, both physical and virtual, then whatever societies embrace that will have to be loose enough to allow for a great deal of internal diversity and multiplicity. That seems like a healthy condition to me. It certainly presents individuals with more options, with more opportunities for choice.
That doesn't imply the end of religion, but it does seem to imply that religions can only be binding on individuals and on voluntary associations of like-minded individuals, and not on everyone in the broader society as a whole.
The other alternative seems to be to seal one's society off, in particularist traditionalist-inspired opposition to the kind of heterogeneity that modern technological change seems to have thrust upon everyone else.
My sense is that the growing wave of fundamentalist Islam is in part about choosing the second separatist course of enforced internal homogeneity, in accordance with what all are expected to acknowledge as God's revealed Law.