CRM - wanky word for teamwork, not convinced that any of the courses out there change how people do it. Some are good at it, some are not. Mostly seems to stay that way.
Ergonomic design- critically important in operational effectivness and efficiency. No effect on safety whatsoever unless it gets to catastrophically bad levels. Not the case in anything we currently fly. The pilot decides how safe the aircraft is by how he operates it. If the aircraft is the equivalent of the iphone, ie just about the perfect ergonomic design, them he can put nearly his entire capacity into fighting the aircraft, as safety requires negligible workload. If it is a dog then it might only leave him 5% of his capacity to fight, and the rest commited to just staying safe. In both cases safety is, or should be, the same, but one is the vastly more effective weapon.
Of course there are limitations to human factors, but trying to squirm and say that pilot error is attributable to all these other pressures is just a manifestation of the modern fad for failing to take personal responsibility.
If you are the pilot, and you crash a servicable aircraft, then it is almost always your fault, end of.