Interestingly, for the last question, I thought about it, and came to the conclusion that hyper-intelligence isn't a great survival trait.
The last one wasn't about survival itself, but rather just tied to the article I linked. Super intelligence wouldn't preclude farmers either. I think if people were truly super intelligent, they would realise what is actually required and what actually has value - rather than the smartest people on earth, building financial derivative products to generate monetary wealth.
It might also make sense if a colony was a cluster of smaller settlements in a region rather than one big city.
For sure. But, it wasn't the point of this piece! :D One city is a major risk factor. Centralisation sucks :D