I don't feel Nashira's looking for history so much as suggestions on how to make the Rotunda more desireable to players, and clearer in rules and regulation.
I like Gabriel's suggestion, really. It's simplistic to put everything into categories in that manner, but at the end of the day, it gets the job done. Different types of people are going to react to different types of people, differently - that's true of any city, and especially one as diverse as Waterdeep. Common sense, however, tells us that the basic races are easily welcomed in the 'Deep; weird things - Centaurs, using Gab's example - won't be driven out of town, but a sudden, huge congregation of them is likely to attract a lot of attention; and the Drow (Eilstraee's followers or not) should not be waltzing down the main roads of the 'Deep as often as they can.
The City of Splendors is so typically diverse in most canon that, while it may cause some stares, excitement, and fear, anything that a group of adventurers can barter with and hasn't attempted to raze a Faerunian city in the last hundred years or so may be able to move through the city unmolested. Are things like centaur, Drow, Tieflings, and what have you rare? Excessively. But elsewise.. the City of Splendors has always reminded me, at least, of Sigil... sans good-evil 'neutrality' and with a far, far greater exercise in caution.