Zardnaar
Legend
Humanocentric isn't the same as xenophobic, and I have yet to see where Gygax has said that xenophobia is a feature of the Flanaess. Heck, even hobgoblins and orcs are fairly common as mercenaries in some locations (such as the Great Kindom and its peripheries).
Also, the inclusion of something "new" doesn't make the setting "anything goes", that's just silly.
As for grittier than FR... Not until From the Ashes. There was nothing inherently gritty about the orginal folio or boxed set—it was pretty much a blank slate.
PHB 1E racial antipathy tables and Gygax's writings on the subject.
I'm not saying pitchforks and hangings but anything more monstrous than say a half orc is gonna have a rough time in a lot of areas.
Espicially Tieflings because of Iuz. Drow maybe although they might benefit from being to mysterious relative to FR Drow.