On a macroscopic scale I think you are totally right, we do need a distribution of a range of skills and IQ points are obviously one of these. But I would point out that the Bell curve is a result of a natural process of lifestage selection and that even if we did bump up our kids' IQ's to 165 or something, the curve would remain intact, even if it ranged over a shorter period. I imagine that most of the social relations would also remain intact as well, although social change would speed up with a more fluid arena for cultural values.

Then there is the point about evolution itself, after all maybe intelligent people are more able to evolve in the timeframe of their lives, and be able to respond in a way that makes them more successful emotionally as well as intellectually. Perhaps that allows them to teach their children more fully and also of course to breed more successfully. Perhaps there are more strands to evolution than even the creator of this node foresaw.