Much food for thought! Digging into these concepts and suggestions has made me think a lot more about the subtle things that are woven into town planning and design that I'd totally taken for granted.
According to interviews she conducted, lots of people think diversity is great, but haven't really considered the role design plays in facilitating that. Interestingly, a lot of her proposals seem to match things that have been implemented in Singapore already, like creating semi-enclosed neighbourhood spaces and playgrounds to unite families over the care of their kids. On the contrary, despite racial quotas in HDBs and stuff, how much interracial interaction do we get to see? How much of any interaction at all?
(A: actually it was a pretty awesome amount when I was a kid running around the blocks with the other kids)
Ultimately a healthy balance of diversity is something that needs an integration of both top-down and bottom-up initiatives to help sustain the stable growth of a diverse community. And the possibilities for design to play a part in them are endless and exciting.