I always research my cities. But that’s me, and research is fun for me.
 
I think, and this applies even when you research, that the bridge between “make it up, real politics are dull” and “think about intersectionality” is that the sweet spot for US seems to be less “real world” and more like “real humanity.” Which is to say, it matters a lot less if you know about the history of the Taylor Creek Rehabilitation Council and how they changed the landscape of Toronto, and a lot more that you know that rich people make nicer parks by kicking poor people out.
 
I mean, obviously there are limits. If you don’t know about how intersectionality works at all, it’s going to be rough. If you have no idea how gangs work, your gangs are going to be movie gangs and not real life ones — and thus likely to suck a bit. But in general I personally interpret the advice as much more “make it like your understanding of how people work in preassurized urban environments” and much less as “make sure you know the 25b only runs until midnight, because Rob Ford fucked over Transit City and now you’re stuck on fucking Don Mills at 1 in the morning.”
 
Also, at some point I should kick my settings for Toronto and Transnistria into shape where other people could use them.

The whole issue of superfriends is a separate one. One thing I will warn you about with that — try to avoid Buffy teams and clear and obvious Big Bads that are clear and obvious EVIL. The debts system works best when everyone is a bit dirty and everyone is in to someone. And when the PCs are not loyal unto the death to each other by default.